United States Office of Ground Water EPA/816-R-99-014u

Environmental and Drinking Water (4601)September 1999

Protection Agency 

The Class V Underground Injection

Control Study

Volume 21

Aquifer Recharge and Aquifer Storage

and Recovery Wells
September 30, 1999

Table of Contents

Page

1. Summary .............................................................. 1

2. Introduction ............................................................ 2

3. Prevalence of Wells ...................................................... 4

4. Injectate Characteristics and Injection Practices ................................ 8

4.1 Injectate Characteristics ............................................. 8

4.1.1 Aquifer Recharge Wells ....................................... 8

4.1.2 ASR Wells ................................................ 15

4.2 Well Characteristics ............................................... 27

4.2.1 Design Features ............................................ 27

4.2.2 Siting Considerations ........................................ 29

4.3 Operational Practices .............................................. 31

5. Potential and Documented Damage to USDWs ............................... 32

5.1 Injectate Constituent Properties ...................................... 32

5.2 Observed Impacts ................................................. 33

6. Best Management Practices ............................................... 33

6.1 Aquifer Recharge and ASR Wells .................................... 33

6.1.1 Recharge Water Quality ...................................... 33

6.1.2 Water Monitoring in Recharge Projects .......................... 34

6.1.3 Physical, Biological, Chemical, and Mechanical Clogging ........... 34

6.2 ASR Wells ...................................................... 37

6.2.1 Location and Spacing of ASR Wells and Impact on Static 

Ground Water Levels ........................................ 37

6.2.2 Operation and Maintenance Practices for ASR Wells ............... 37

7. Current Regulatory Requirements .......................................... 38

7.1 Federal Programs ................................................. 38

7.1.1 SDWA ................................................... 38

7.1.2 Other Federal Rules and Programs ............................. 40

7.2 State and Local Programs .......................................... 42

Attachment A: ASR Well Data Reported in Literature ................................ 45

Attachment B: ASR Facilities and Wells in Florida .................................. 47

Attachment C: State and Local Program Descriptions ................................ 49

References .................................................................. 66
 Aquifer recharge and ASR well injecting only treated wastewater are addressed separately in 1

the sewage treatment effluent well summary, which is Volume 7 of the Class V UIC Study.

September 30, 1999 1

AQUIFER RECHARGE AND 

AQUIFER STORAGE AND RECOVERY WELLS

The U.S. Environmental Protection Agency (USEPA) conducted a study of Class V

underground injection wells to develop background information the Agency can use to evaluate

the risk that these wells pose to underground sources of drinking water (USDWs) and to

determine whether additional federal regulation is warranted. The final report for this study,

which is called the Class V Underground Injection Control (UIC) Study, consists of 23 volumes

and five supporting appendices. Volume 1 provides an overview of the study methods, the

USEPA UIC Program, and general findings. Volumes 2 through 23 present information

summaries for each of the 23 categories of wells that were studied. This volume, which is

Volume 21, covers two Class V well categories: aquifer recharge and aquifer storage and

recovery (ASR) wells.

1. SUMMARY

Aquifer recharge and ASR wells are used to replenish water in an aquifer for subsequent

use. While an aquifer recharge well is used only to replenish the water in an aquifer, ASR wells

are used to achieve two objectives: (1) storing water in the ground; and (2) recovering the stored

water (from the same well) for a beneficial use. Both of these types of wells, however, may have

secondary objectives, such as subsidence control and prevention of salt water intrusion into fresh

water aquifers. Aquifer recharge and ASR wells are found in areas of the U.S. that have high

population density and proximity to intensive agriculture; dependence and increasing demand on

ground water for drinking water and agriculture; and/or limited ground or surface water

availability. ASR wells are also found in areas that have no freshwater drinking water supplies,

or in coastal areas where salt water intrusion into freshwater aquifers is an issue. 

Aquifer recharge and ASR well injectate consists of potable drinking water (from a

drinking water plant), ground water (treated or untreated), and surface water (treated or

untreated). Water injected into aquifer recharge and ASR wells is typically treated to meet 1

primary and secondary drinking water standards. This is done to protect the host aquifer and to

ensure that the quality of the ground water to be recovered is adequate for subsequent use. In

addition, most regulatory agencies require the injectate in aquifer recharge and ASR wells to

meet drinking water standards in order to prevent degradation of ambient ground water quality.

However, it should be noted that, in some instances, constituents have been measured at

concentrations slightly above drinking water standards. 

Aquifer recharge and ASR wells are drilled to various depths depending on the depth of

the receiving aquifer. They may inject into confined, semi-confined, or unconfined aquifers,

although most of these wells inject into semi-confined aquifers that have been partially

dewatered due to overpumping. 
September 30, 1999 2

No contamination incidents associated with the operation of aquifer recharge or ASR

wells have been reported.

Because the major goal of aquifer recharge and ASR wells is to replenish water in

aquifers for subsequent use and its injectate typically meets drinking water standards, aquifer

recharge and ASR wells are unlikely to receive spills or illicit discharges.

According to the state and USEPA Regional survey conducted for this study, there are

approximately 1,185 aquifer recharge and ASR wells documented in the U.S. This total includes

807 aquifer recharge wells, 130 ASR wells, and 248 wells (in California and Idaho) that cannot

be distinguished among aquifer recharge and ASR wells in the available inventory. The

estimated number of aquifer recharge and ASR wells in the nation is greater than 1,695, but

unlikely to be higher than 2,000. This estimate does not include 200 wells proposed to be built

in Florida as part of the "Everglades Restoration Project." Approximately 89 percent of the

documented aquifer recharge and ASR wells are located in ten states: California (200),

Colorado (9), Florida (<488), Idaho (48), Nevada (110), Oklahoma (44), Oregon (16), South

Carolina (55), Texas (67), and Washington (12). Wisconsin has conditionally approved one

ASR well as part of a pilot study at a municipal water system in Oak Creek, and a second pilot

project in Green Bay, Wisconsin is under development. The project in Green Bay is expected to

be operational within the next year.

The statutory and regulatory requirements differ significantly among the ten states where

the majority of the aquifer recharge and ASR wells are believed to exist. In California and

Colorado, USEPA Regions 9 and 8, respectively, directly implement the UIC program for Class

V injection wells. However, both states have additional jurisdiction over aquifer recharge and

ASR wells through state regional water quality control boards in California and permitting of

extraction and use of waters artificially recharged in Colorado. The remaining eight states are

UIC Primacy States for Class V wells. Oklahoma and Texas are UIC Primacy States that

authorize aquifer recharge and ASR wells by rule, while Florida, Nevada, Oregon, South

Carolina, and Washington require individual permits for the operation of aquifer recharge and

ASR wells. In Idaho, construction and operation of shallow injection wells (<18 feet) is

authorized by rule; construction and use of a deep injection well ($18 feet) requires an individual

permit. 

2. INTRODUCTION

Ground water is being increasingly used for agricultural, drinking, and industrial supplies

in the United States. As a result, the available supply of fresh ground water is decreasing at an

accelerated rate, and water managers and planners have been faced with the challenge of

developing water management techniques to meet water demands (O'Hare et al., 1986; Pyne,

1995). 

One technique that has been used in recent years is artificial aquifer recharge. Artificial

recharge refers to the movement of water via man-made systems from the surface of the earth to

underground water-bearing strata where it may be stored for future use (Griffis, 1976). Such

recharge may be conducted for ground water resource management, water storage and recovery,
September 30, 1999 3

prevention of salt water intrusion into fresh water aquifers, and subsidence control, among other

purposes (Bouwer et al., 1990; Crook et al., 1991; Fairchild, 1985; Hamlin, 1987; North Carolina

Division of Water Resources, 1996). 

The advantages of aquifers over surface water impoundments as reservoirs for cyclic

storage of water are: (1) permanence; (2) no loss of storage capacity due to sedimentation; (3) no

loss of water due to evaporation; (4) less vulnerability to destruction and contamination; and (5)

the absence of threat to downstream communities (by eliminating the possibility of dams

breaking and floods occurring) (Kazmann, 1967). 

Conventional methods of artificial recharge include surface spreading, infiltration pits

and basins, and injection wells. Injection wells are the selected method of artificial recharge in

areas where the existence of impermeable strata between the surface and the aquifer makes

recharge by surface infiltration impractical or in areas where land for surface spreading is

limited. 

 

During the last 30 years, a special type of recharge well has been developed: ASR wells

(Wilson, 1999; Pyne, 1995). What distinguishes an ASR well from an aquifer recharge well is

its dual-purpose characteristic. While an aquifer recharge well is used only to replenish the

water in an aquifer, ASR wells are used to achieve two objectives: (1) storing water in the

ground; and (2) recovering the stored water (from the same well) for a beneficial use. 

This summary addresses both aquifer recharge and ASR wells. These types of wells

usually inject water into water supply aquifers. According to the existing UIC regulations in 40

CFR 146.5(e)(6), “recharge wells used to replenish the water in an aquifer” are considered Class

V injection wells. ASR wells are considered Class V injection wells under the existing UIC

regulations in 40 CFR Parts 144 and 146, but ASR wells are not specifically defined in the

regulations. 

Aquifer recharge and ASR wells that only inject reclaimed wastewaters are addressed

separately in the sewage treatment effluent well summary, which is Volume 7 of the Class V

UIC Study (the wells covered in this volume, Volume 21, do not inject sewage treatment effluent

or inject such effluent mixed with ground water and/or surface water). Aquifer recharge wells

used primarily for subsidence control or prevention of salt water intrusion into fresh water

aquifers are addressed in Volumes 20 and 23 of the Class V UIC Study, respectively.

Connector wells, which create a direct connection, or bore hole, from one aquifer to

another, are designed to drain surficial aquifers into a deeper aquifer and are used solely for

dewatering purposes, not in a recharge capacity. Thus, connector wells are considered special

drainage wells and are not included in this volume. For further information on connector wells,

see the special drainage information summary, which is Volume 14 of the Class V UIC Study. 

Storm drainage wells, which may provide aquifer recharge while disposing of excess storm

water, are addressed separately in Volume 3 of the Class V UIC Study.
September 30, 1999 4

3. PREVALENCE OF WELLS

The primary factors for locating aquifer recharge and ASR wells include: population

density and proximity to intensive agriculture in a low moisture region; dependence and

increasing demand on ground water for drinking water and agriculture; high seasonal

fluctuations in water demand and availability; and limited ground or surface water availability. 

ASR wells are also found in areas that have no fresh water drinking water supply, or in coastal

areas where salt water intrusion into freshwater aquifers is an issue. Densely developed areas

tend to use recharge wells, while the Central and Western Plains States have more available open

land and are more likely to use recharge basins and infiltration areas. As the population grows,

as adequate land for the construction of surface reservoirs becomes increasingly scarce, and as

water sources become more limited, the use of aquifer recharge and ASR wells is expected to

increase. 

Three studies looked at potential siting and future needs for artificial aquifer recharge. 

Culp (1981) developed water use and ground water mining projections for areas of the country

and identified the Great Plains and the southwest United States as requiring recharge or some

other action to alleviate water shortages. O’Hare et al. (1986) used a model based on agriculture

needs to identify areas for aquifer recharge. The model identified central areas of the Great

Plains and areas along the west and southeastern coasts of the United States. Fairchild (1985)

identified areas suitable for aquifer recharge in combination with a need for preventing salt water

intrusion. The areas suitable for recharge, according to Fairchild, corresponded to the same

areas identified by O’Hare (1986): central areas of the Great Plains and areas along the west and

southeastern coasts of the United States.

For this study, data on the number of Class V aquifer recharge and ASR wells were

collected through a survey of state and USEPA Regional UIC Programs. The survey methods

are summarized in Section 4 of Volume 1 of the Class V UIC Study. Table 1 lists the numbers

of Class V aquifer recharge and ASR wells in each state, as determined from this survey. The

table includes the documented number and estimated number of wells in each state, along with

the source and basis for any estimate, when noted by the survey respondents. If a state is not

listed in Table 1, it means that the UIC Program responsible for that state indicated in its survey

response that it did not have any Class V aquifer recharge or ASR wells.

As shown in Table 1, there are approximately 1,185 aquifer recharge and ASR wells

documented in the United States. This total includes 807 aquifer recharge wells, 130 ASR wells,

and 248 recharge wells (in California and Idaho) that cannot be distinguished among aquifer

recharge and ASR wells in the available inventory. The estimated number of aquifer recharge

and ASR wells in the nation is believed to be greater than 1,695 (1,300 aquifer recharge wells,

147 ASR wells, and the 248 wells in California and Idaho that are either aquifer recharge or ASR

wells. These estimates include 404 in Florida that were reported as aquifer recharge wells. 

However, there is a possibility that a high number of these 404 wells are storm drainage wells or 
September 30, 1999 5

Table 1. Inventory of Aquifer Recharge and 

Aquifer Storage and Recovery Wells in the United States

State Well Documented

Number of Wells 

Estimated Number of Wells Type of

Number Source of Estimate and Methodology (AR/ASR) 1

USEPA Region 1

NH 2 2 N/A AR

USEPA Region 2

NJ

NR NR N/A AR

10 NR N/A ASR 2

NY 0 500 Best professional judgement. AR

USEPA Region 3

DE 2 2 N/A ASR

PA NR NR N/A AR

VA

NR NR N/A AR

1 NR N/A ASR 2

WV 1 1 State officials believe that the documented number AR

of aquifer recharge wells in the state is accurate.

USEPA Region 4

FL

< 404 < 404 N/A AR

>84 wells at >84 wells at N/A ASR

28 facilities 28 facilities

(200 more wells to

be built)

NC 0 0 Aquifer recharge wells are not being used to date, AR

but state officials note that they are aware of plans

to construct this type of well in the future.

SC 55 55 N/A AR

TN 1 NR N/A ASR 3

USEPA Region 5

IL 5 2 The Illinois Environmental Protection Agency has AR

recent documentation for just two wells and believes

that only two are still operating. The last

correspondence on these wells was in May 1996.

WI 1 1 One pilot test well approved conditionally as part of ASR

an American Water Works Association Research

Foundation study (Wilson, 1999).
Table 1. Inventory of Aquifer Recharge and 

Aquifer Storage and Recovery Wells in the United States (continued)

State Well Documented

Number of Wells 

Estimated Number of Wells Type of

Number Source of Estimate and Methodology (AR/ASR) 1

September 30, 1999 6

USEPA Region 6

OK 44 44 N/A AR

TX

66 66 N/A AR

1 1 N/A ASR

USEPA Region 7

IA 1 1 N/A ASR

KS 1 1 N/A ASR

USEPA Region 8

CO

2 NR N/A AR

7 7 N/A ASR

SD 1 1 N/A AR

UT 3 > 3 Inventory forms received in fiscal year 1998 are not ASR

reflected in the documented number because of an

anticipated change in data systems.

WY 3 wells/1 site 3 wells/1 site Best professional judgement. The additional wells AR

(WDEQ) listed in the WY Database were never constructed or

 6 sites

 (WY Database) 

were closed shortly after commencing operations.

USEPA Region 9

AZ 2 > 2 Best professional judgement (Olson, 1999). AR

CA 81 (Region 9) 81 (Region 9) USEPA Region 9 does not distinguish between ASR AR/ASR

200 (Central Valley 200 (Central Valley the inventory. Therefore, the exact number of ASR

Region) Region) wells cannot be determined by examining the

and aquifer recharge wells; both are coded 5R21 in

inventory.

County and State Regional Water Quality Control

Boards maintain Class V inventories. The extent to

which USEPA Region 9 inventory data overlap

county and state inventory data is unknown.

GU 102 NR Documented number of wells was obtained from AR

Region database. However, Region acknowledges

that this database is not entirely accurate because

Guam was granted Primacy for the Class V UIC

program in May 1983. 

NV 110 110 N/A AR
Table 1. Inventory of Aquifer Recharge and 

Aquifer Storage and Recovery Wells in the United States (continued)

State Well Documented

Number of Wells 

Estimated Number of Wells Type of

Number Source of Estimate and Methodology (AR/ASR) 1

September 30, 1999 7

USEPA Region 10

ID 48 48 This number combines ASR and aquifer recharge AR/ASR

wells, both of which are coded as 5R21 wells in the

available inventory (Terada, 1999).

OR

4 0 Best professional judgement (Priest, 1999). AR

12 15 Best professional judgement (Priest, 1999). ASR

WA

6 6 N/A AR

6 < 20 Best professional judgement. ASR

All USEPA Regions

All states

 1,185 > 1,695

(807 AR, 130 ASR, (1,300 AR, 147 ASR,

and 248 AR/ASR) and 248 AR/ASR)

Total estimated number counts the documented

number when estimate is NR.

Estimated number of wells does not include 200 ASR

ASR wells proposed to be built in Florida as part of

the new "Everglades Project."

AR and

 Unless otherwise noted, the best professional judgement is that of the state or USEPA Regional staff completing the survey 1

questionnaire.

 The number of documented wells was not reported by the USEPA Region or the state. Number of wells was obtained from 2

literature.

 This injection well was permitted as an experimental well because, although ASR technology had been demonstrated in other 3

states, this is the first such system to be constructed in Tennessee (TDEC, 1996a, 1996b). 

AR Aquifer recharge well.

ASR Aquifer storage and recovery well.

N/A Not available.

NR Although USEPA Regional, state, and/or territorial officials reported the presence of the well type, the number of 

wells was not reported, or the questionnaire was not returned.
September 30, 1999 8

connector wells (Deuerling, 1999). It should also be noted that the estimated number of aquifer

recharge and ASR wells does not include 200 ASR wells proposed to be built in Florida as part

of the "Everglades Restoration Project." 

The Everglades Restoration Project, officially known as the Central and South Florida

(C&SF) Project, was authorized by Congress in 1948 and completed by the mid 1960s. It is a

multi-purpose project that provides flood control; water supply for municipal, industrial, and

agricultural uses; prevention of salt water intrusion; water supply for Everglades National Park;

and protection of fish and wildlife resources. The primary system includes about 1,000 miles

each of levees and canals, 150 water control structures, and 16 major pump stations. One set of

problems has given way to a new set of equally critical problems that threatens the final collapse

of what remains of the natural system, along with the resulting impacts to the population and

economy of the region (U.S. Department of the Interior, 1996). 

In 1993, the Army Corps of Engineers initiated a comprehensive review of the C&SF

Project (C&SF Restudy), and a Federal Interagency Task Force, chaired by the Department of

the Interior, was convened to coordinate ongoing restoration efforts and guide the Corps in its

C&SF Restudy. The purpose of the C&SF Restudy was to determine the feasibility of structural

or operational modifications to the project essential to restoration of the Everglades and Florida

Bay ecosystems while providing for other water related needs including urban water supplies

(U.S. Department of the Interior, 1996). 

Additional information on ASR wells is provided in Attachments A and B of this volume. 

 Attachment A provides the location, operational information, storage zone, and number of ASR

wells, as reported in the literature, of some of the ASR facilities in the national inventory. 

Attachment B details the permitting and operational status, as well as type of injectate, of the 28

ASR facilities located in Florida.

 4. INJECTATE CHARACTERISTICS AND INJECTION

PRACTICES

4.1 Injectate Characteristics

4.1.1 Aquifer Recharge Wells

Sources of injectate in aquifer recharge wells known to exist in the United States are

listed in Table 2. As shown in this table, aquifer recharge well injectate consists of treated

drinking water, surface water (treated or untreated), surface runoff, and ground water (treated or

untreated). Treated municipal wastewater (i.e., reclaimed water) also is being used for aquifer

recharge, but wells injecting only this type of fluid are covered in the sewage treatment effluent

well summary, which is Volume 7 of the Class V UIC Study.
September 30, 1999 9

Table 2: Source of Injectate for Aquifer Recharge Wells in the United States1

State Source of Injectate

NH Untreated surface (river) water that meets drinking water standards.

NJ NR

NY Untreated surface water.

PA NR

VA NR

WV Treated drinking water.

FL Treated surface water and reclaimed water.

NC NR

SC Surface water treated to drinking water standards.

IL Surface water from the Illinois River.

OK Unknown.

TX Generally, overland flow.

CO NR

SD Surface water from the James River treated at the City of Huron Water

Treatment Plant prior to injection.

WY Fluids dewatered from a clinker unit of a surface coal mine.

AZ Untreated surface water.

CA Treated ground water.

NV 93 wells inject surface water with disinfection only.

17 wells inject untreated ground water at mine dewatering sites.

GU NR

ID 47 wells inject untreated surface water.

1 well injects water treated to drinking water standards.

OR 3 wells inject shallow (<50 feet) ground water.

1 well injects surface water treated with disinfection only.

WA Treated water. Treatment depends on background water quality.

 All data presented in the table were obtained from states and USEPA Regions. 1

NR Not reported.
September 30, 1999 10

Two aquifer recharge projects in the High Plains Region of the United States provide

examples of the quality of water being injected into aquifer recharge wells. The first example is

the Huron Project in South Dakota. This aquifer recharge project uses high flows from the

James River during the spring runoff period as a source of water, treats this water in the City of

Huron’s water treatment plant, and injects the water into the Warren Aquifer. The Huron Project

is one of the projects implemented by the Bureau of Reclamation and local sponsors in

cooperation with USEPA and the United States Geological Survey under the "High Plains States

Ground Water Demonstration Program Act of 1983," Public Law 98-434 (the Act). The Act

authorizes and directs the Secretary of the Interior, acting through the Bureau of Reclamation, to

engage in a special study of the potential for ground water recharge in the High Plains States

(Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming)

and other Reclamation Act States (Arizona, California, Idaho, Montana, Nevada, North Dakota,

Oregon, Utah, and Washington) (Schaefer et al., 1994). The primary purpose of the Act is to

advance the state-of-the-art in ground water recharge techniques (U.S. Bureau of Reclamation,

1996). For each demonstration program established under the Act, monitoring data have to be

collected for a period of four to five years and a final report has to be submitted to Congress. A

summary report will be submitted to Congress at the conclusion of the demonstration projects,

currently estimated to be early in fiscal year 2000 (U.S. Bureau of Reclamation, No date #1). 

Injectate data for the Huron Project in South Dakota, along with drinking water standards

for the purpose of comparison, are presented in Table 3. As seen in the table, all constituents

analyzed, except fluoride, meet primary and secondary drinking water standards. For fluoride,

concentrations ranging between 8 and 14 mg/l were measured. The primary drinking water

standard for fluoride is 4 mg/l.

The second example is the use of aquifer recharge wells in the High Plains Region of

Texas. This type of well is used to recharge ground water aquifers when surface water is in

surplus. Constituent concentrations in waters of the High Plains Aquifer and in recharge waters

are presented in Table 4. Comparison of constituent concentrations in aquifer waters with

corresponding recharge waters suggest that the injected water may often be of better quality than

that of the receiving aquifer. In addition, all constituents in the recharge waters, for which

chemical analysis data are available, meet drinking water standards. The only exception is the

recharge waters of Hockley County for which the pH was 9. The secondary drinking water

standard for pH is 6.5 to 8.5.
September 30, 1999 11

Table 3. Injectate Data for Recharge Water Used in the Huron Project

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Range of Concentrations 1

indicated) indicated) indicated)

Organics

Benzene 0.005 (F) 0.1 (F,C) <0.003

Carbon Tetrachloride 0.005 (F) 0.03 (F,C) <0.003

1,2-Dichlorobenzene 0.6 (F) 0.6 (F,N) <0.003

1,3-Dichlorobenzene N/A 0.6 (F,N) <0.003

1,4-Dichlorobenzene 0.075 (F) 0.075 (F,N) <0.003

1,2-Dichloroethane 0.005 (F) 0.04 (F,C) <0.003

1,1-Dichloroethylene 0.007 (F) 0.007 (F,N) <0.003

1,1,1-Trichloroethane 0.2 (F) 0.2 (F,N) <0.003

Trichloroethylene 0.005 (F) 0.3 (F,C) <0.003

Vinyl Chloride 0.002 (F) 0.0015 (F,C) <0.001

2,4-D 0.07 (F) 0.07 (F,N) <0.00001 - 0.00025

2,4,5-T L 0.07 (F,N) <0.00001 - 0.00001

2,4-DP N/A N/A <0.00001 - 0.00001

Aldrin N/A 0.0002 (D,C) <0.00001 - 0.00001

Chlordane 0.002 (F) 0.003 (F,C) <0.00001 - 0.0001

DDD N/A N/A <0.00001 - 0.00001

DDE N/A N/A <0.00001 - 0.00001

DDT N/A N/A <0.00001 - 0.00001

Dieldrin N/A 0.0002 (F,C) <0.00001 - 0.00001

Endosulfan I N/A N/A <0.00001 - 0.00001

Endrin 0.002 (F) 0.002 (F,N) <0.00001 - 0.00001

Heptachlor 0.0004 (F) 0.0008 (F,C) <0.00001 - 0.00001

Heptachlor Epoxide 0.0002 (F) 0.0004 (F,C) <0.00001 - 0.00001

Lindane 0.0002 (F) 0.0002 (F,N) <0.00001 - 0.00001

Methoxychlor 0.04 (F) 0.04 (F,N) <0.00001 - 0.00001

Mirex N/A N/A <0.00001 - 0.00001

Perthane N/A N/A <0.0001 - 0.0001
Table 3. Injectate Data for Recharge Water Used in the Huron Project (continued)

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Range of Concentrations 1

indicated) indicated) indicated)

September 30, 1999 12

Polychlorobiphenyls 0.0005 (F) 0.0005 (P,C) <0.0001 - 0.0001

Polychlorophthalenes N/A N/A <0.0001 - 0.0001

Silvex (2,4,5-TP) 0.05 (F) 0.05 (F,N) <0.00001 - 0.00001

Toxaphene 0.003 (F) 0.003 (F,C) <0.001 - 0.001

Dichlorobromomethane N/A N/A 0.0075 - 0.021

Bromoform 0.1 (P) 0.4 (D,C) <0.003

Chlorodibromomethane 0.1 (P) 0.06 (D,N) 0.0035 - 0.017

Chloroform 0.1 (P) 0.6 (D,C) 0.0093 - 0.021

Inorganics

Arsenic 0.05 (R) 0.002 (D,C) <0.001

Barium 2 (F) 2 (F,N) 0.012 - 0.020

Beryllium 0.004 (F) 0.0008 (D,C) <0.0005

Boron L 0.6 (D,N) 0.2 - 0.4

Cadmium 0.005 (F) 0.005 (F,N) <0.001

Calcium N/A N/A 37 - 53

Chloride Secondary MCL: 250 (F) N/A 69 - 100

Chromium 0.1 (F) 0.1 (F,N) <0.005

Cobalt N/A N/A <0.003

Copper 1.3 (F) (action level, at tap) N/A <0.01

Secondary MCL: 1 (F)

Fluoride 4 (F,R) N/A 8 - 14i

Secondary MCL: 2 (F)

Iron Secondary MCL: 0.3 (F) N/A 0.005 - 0.009

Lead 0.015 (action level, at tap) (F) N/A <0.01

Lithium N/A N/A 0.05 - 0.07

Magnesium N/A N/A 12 - 20

Manganese L N/A 0.002 - 0.003

Secondary MCL: 0.05 (F)

Mercury 0.002 (F) 0.002 (F,N) <0.0001

Molybdenum L 0.04 (D,N) <0.01 - 0.01

Nickel 0.1 (F) 0.1 (F,N) <0.01 2
Table 3. Injectate Data for Recharge Water Used in the Huron Project (continued)

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Range of Concentrations 1

indicated) indicated) indicated)

September 30, 1999 13

Ammonia N/A 30 (D,N) 0.59 - 0.98

Nitrate, as N 10 (F) N/A <0.1 - 0.1

Phosphorus N/A N/A 0.578 - 0.593

Orthophosphorus N/A N/A 0.02 - 0.063

Potassium N/A N/A 17 - 23

Selenium 0.05 (F) N/A <0.001

Silica N/A N/A 4.6 - 8.8

Silver Secondary MCL: 0.1 (F) 0.1 (D,N) <0.001

Sodium N/A D 100 - 190

Strontium N/A N/A 0.24 - 0.37

Sulfate 500 (P) D 230 - 440

Secondary MCL: 250 (F)

Vanadium T D <0.006

Zinc L 2 (D,N) <0.003 -0.004

Secondary MCL: 5 (F)

Radionuclides

Gross Beta, as CS-137 4 mrem/y (27.7 pCi/l) (F) 4 mrem/y (27.7 pCi/l) (C) 7.5 - 24 pCi/l

Gross Beta, as SR/YT-90 4 mrem/y (27.7 pCi/l) (F) 4 mrem/y (27.7 pCi/l) (C) 5.6 - 18 pCi/l

Gross Alpha, as U-Nat 15 pCi/l (F) 15 pCi/l (C) <0.4 - 1.2 pCi/l

Radium 226/228 Combined Radium 226 and Combined Radium 226 and 0.1/0 pCi/l

228: 5 pCi/l (F) 228: 20 pCi/l (C)

Data Sources: South Dakota State University, 1993 and U.S. Bureau of Reclamation, No date #2

 Primary maximum contaminant level (MCL), unless otherwise noted. 1

 Being remanded. 2

Regulatory Status:

F Final P Proposed

D Draft R Under Review

L Listed for regulation T Tentative (not officially proposed)

Health Advisory:

C 10 cancer risk N Noncancer lifetime -4

N/A Not available.

i Exceeds primary and secondary drinking water standards.
September 30, 1999 14

Table 4. Constituent Concentrations in Aquifer and Recharge Waters, High Plains Aquifer, TX

Parameter (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level 1

indicated) indicated)

Concentrations at Concentrations at Concentrations at 

Dawson County Well Hockley County Well Edwards County Well 2

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

2 3

Aquifer Recharge Aquifer Recharge Aquifer Recharge

Waters Waters Waters Waters Waters Waters

Nitrate 10 (F) N/A 43 0.04 8.4 0.04 7.2 0.04

Silica N/A N/A 70 2 50 2 11 11

Calcium N/A N/A 61 39 60 27 63 60

Magnesium N/A N/A 53 3 88 7 8 1

Sodium N/A D 65 25 61 15 8 6

Potassium N/A N/A 8 6 — 6 — 12

Carbonate N/A N/A — 0 — 6 — 0

Bicarbonate N/A N/A 375 113 337 87 211 183

Sulfate 500 (P) D 81 32 218 24 7 10

Secondary MCL: 250 (F)

Chloride Secondary MCL: 250 (F) N/A 68 33 86 20 15 15

Fluoride 4 (F,R) N/A 4.5 0.3 4.4 0.5 0.2 0.1

Secondary MCL: 2 (F)

pH Secondary MCL: 6.5 - 8.5 N/A 7.8 8.3 8.4 9i 8.1 8

Total Dissolved Solids Secondary MCL: 500 (F) N/A 637.8 206 741.5 154 223.1 222

Data Source: Texas Department of Water Resources, 1984

 Primary maximum contaminant level (MCL), unless otherwise noted. 1

 Ogallala Aquifer. 2

 Edwards Aquifer. 3

Regulatory Status: F: Final; D: Draft; R: Under Review

N/A Not available.

i Exceeds secondary drinking water standard.
September 30, 1999 15

4.1.2 ASR Wells

Sources of injectate in ASR wells known to exist in the United States are listed in Table

5. As shown in the table, ASR well injectate consists of potable drinking water (from a drinking

water plant), surface water (treated or untreated), ground water (treated or untreated), and

reclaimed water. For further discussion on ASR wells injecting reclaimed water, see the sewage

treatment effluent well summary, which is Volume 7 of the Class V UIC Study.

Table 5: Source of Injectate for ASR Wells in the United States1

State Source of Injectate

NJ NR

DE Ground water from another aquifer; the water may be treated and disinfected.

VA NR

FL Treated potable drinking water (from a drinking water plant), untreated (raw)

ground water, untreated (raw) surface water, reclaimed water, and partially

treated surface water.

WI Surface water treated to drinking water standards.

TX Surface water treated to drinking water standards.

IA Surface water treated to drinking water standards.

KS Untreated ground water infiltrated from the Little Arkansas River.

CO Surface water treated to drinking water standards.

UT Surface and spring water treated to drinking water standards.

CA Treated ground water.

OR Surface water treated to drinking water standards.

WA Surface water treated to drinking water standards. The Washington State

Legislature recently authorized injection of treated wastewater (tertiary

treatment) on a pilot basis. To the state’s knowledge, none of this type of well

currently exists, but activity is expected in the near future.

 All data presented in the table were obtained from states and USEPA Regions. 1

NR Not reported.

In cases where injectate constituents react with ambient ground water causing an increase

in constituent concentrations or the formation of new compounds, pretreatment techniques are

used. For example, injectate of ASR wells at the Swimming River site in New Jersey is

pretreated in order to control excessive iron concentrations (i.e., concentrations above secondary

drinking water standards) in the recovered water. These techniques involve lowering pH to

control the precipitation of ferric hydroxide floc in the aquifer, followed by a buffer volume of

deoxygenated water at normal pH. 
September 30, 1999 16

To provide a representative characterization of the injectate used in ASR operations,

injectate data from four facilities are summarized in Tables 6 through 8. For the purpose of

comparison, the tables also present available drinking water standards. A brief discussion of

these data follows.

Table 6 presents injectate data for the ASR wells operated by the Centennial Water and

Sanitation District, Denver, Colorado. The injectate in these wells is treated surface water and

treated ground water, when surface water is not readily available. As shown in this table, the

only two constituents that do not meet the primary drinking water standards are radium and lead. 

For radium (radium 226 and 228), a concentration of 5.03 pCi/l was found during one of the

sample events (July 28, 1998). The primary drinking water standard for combined radium 226

and 228 is 5 pCi/l. For lead, a concentration of 0.025 mg/l was found in one of the samples

(February 11, 1998). The action level for lead is 0.015 mg/l, at the tap. 

Table 7 presents injectate data for the four ASR wells at Woodmansee Park in the City of

Salem, Oregon. These ASR wells, which inject treated surface water, are being used as a

secondary source of water for emergency needs and for supplemental needs during high water

use summer seasons. As shown in the table, all constituents analyzed meet drinking water

standards.

Table 8 presents injectate data for the ASR well operated by the Memphis Light, Gas,

and Water Division (MLGWD). This well injects treated drinking water. As shown in Table 8,

the injectate meets primary drinking water standards for all constituents analyzed. 

As mentioned earlier, 200 new ASR wells have been proposed to be used as part of the

C&SF Restudy. These wells would inject untreated surface water, which will not meet primary

or secondary drinking water standards at the point of discharge (Wilson, 1999).
September 30, 1999 17

Table 6. Injectate Data for the ASR System 

at Centennial Water and Sanitation District, Highlands Ranch, Colorado

Parameter Drinking Water Standard Health Advisory Level Range of Concentrations 1

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

Volatile Organic Chemicals

Benzene 0.005 (F) 0.1 (F,C) <MDL

Bromobenzene L D <MDL

Bromodichloromethane 0.1 (P) 0.06 (D,C) 0.011 - 0.027

Bromoform 0.1 (P) 0.4 (D,C) 0.0011 - 0.0066

Bromomethane T 0.01 (D,N) <MDL

Carbon Tetrachloride 0.005 (F) 0.03 (F,C) <MDL

Chlorobenzene N/A N/A <MDL

Chloroethane L D <MDL

Chloroform 0.1 (P) 0.6 (D,C) 0.011 - 0.018

Chloromethane L 0.003 (F,N) <MDL

o-Chlorotoluene L 0.1 (F,N) <MDL

p-Chlorotoluene L 0.1 (F,N) <MDL

Dibromomethane L N/A <MDL

m-Dichlorobenzene (1,3- N/A 0.6 (F,N) <MDL

Dichlorobenzene)

o-Dichlorobenzene (1,2- 0.6 (F) 0.6 (F,N) <MDL

Dichlorobenzene)

p-Dichlorobenzene (1,4- 0.075 (F) 0.075 (F,N) <MDL

Dichlorobenzene)

1,1-Dichloroethane N/A N/A <MDL

1,2-Dichloroethane 0.005 (F) 0.04 (F,C) <MDL

1,1-Dichloroethylene 0.007 (F) 0.007 (F,N) <MDL

cis-1,2-Dichloroethylene 0.07 (F) 0.07 (F,N) <MDL

trans-1,2-Dichloroethylene 0.1 (F) 0.1 (F,N) <MDL

Dichloromethane (Methylene Chloride) 0.005 (F) 0.5 (F,C) <MDL

1,2-Dichloropropane 0.005 (F) 0.06 (F,C) <MDL

1,3-Dichloropropane L D <MDL

2,2-Dichloropropane L D <MDL

1,1-Dichloropropene N/A D <MDL
Table 6. Injectate Data for the ASR System 

at Centennial Water and Sanitation District, Highlands Ranch, Colorado (continued)

Parameter Drinking Water Standard Health Advisory Level Range of Concentrations 1

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

September 30, 1999 18

1,3-Dichloropropene T 0.02 (F,C) <MDL

Ethylbenzene 0.7 (F) 0.7 (F,N) <MDL

Styrene 0.1 (F) 0.1 (F,N) <MDL

1,1,1,2-Tetrachloroethane L 0.07 (F,N) <MDL

0.1 (F,C)

1,1,2,2-Tetrachloroethane L D <MDL

Tetrachloroethylene 0.005 (F) 0.07 (F,C) <MDL

Toluene 1 (F) 1 (F,N) <MDL

1,1,2-Trichloroethane 0.005 (F) 0.003 (F,N) <MDL

Trichloroethylene 0.005 (F) 0.3 (F,C) <MDL

1,2,3-Trichloropropane L 0.04 (F,N) <MDL

0.5 (F,C)

Vinyl Chloride 0.002 (F) 0.0015 (F,C) <MDL

m-Xylene 10 (F) 10 (F,N) <MDL 2 3

o-Xylene 10 (F) 10 (F,N) <MDL 2 3

p-Xylene 10 (F) 10 (F,N) <MDL 2 3

Inorganics

Arsenic, As (T) 0.05 (R) 0.002 (D,C) <MDL - 0.002

Barium, Ba (T) 2 (F) 2 (F,N) 0.057 - 0.074

Cadmium, Cd (T) 0.005 (F) 0.005 (F,N) <MDL - 0.0001

Chromium, Cr (T) 0.1 (F) 0.1 (F,N) <MDL

Lead, Pb (T) 0.015 (action level, at tap) (F) N/A <MDL - 0.025i

Mercury, Hg (T) 0.002 (F) 0.002 (F,N) <MDL

Selenium, Se (T) 0.05 (F) N/A <MDL - 0.011

Silver, Ag (T) Secondary MCL: 0.1 (F) 0.1 (D,N) <MDL - 0.0003

Sodium, Na (T) N/A D 0.0197 - 0.046

Fluoride, F 4 (F,R) N/A 0.00083 - 0.00089

Secondary MCL: 2 (F)

Nitrogen, Nitrate 10 (F) N/A 0.00009 - 0.00044
Table 6. Injectate Data for the ASR System 

at Centennial Water and Sanitation District, Highlands Ranch, Colorado (continued)

Parameter Drinking Water Standard Health Advisory Level Range of Concentrations 1

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

September 30, 1999 19

Radionuclides

Gross Alpha 15 pCi/l (F) 15 pCi/l (C) 5.3 - 13.8 pCi/l

Gross Beta 4 mrem/y (27.7 pCi/l) (F) 4 mrem/y (27.7 pCi/l) (C) 5.2 - 12.4 pCi/l

Radium 226 0.31 - 2.42 pCi/li Combined Radium 226 and Combined Radium 226 and

228: 5 pCi/l (F) 228: 20 pCi/l (C) Radium 228 1.0 - 2.61 pCi/li

Pesticides

Endrin 0.002 (F) 0.002 (F,N) <MDL

Lindane 0.0002 (F) 0.0002 (F,N) <MDL

Methoxychlor 0.04 (F) 0.04 (F,N) <MDL

Toxaphene 0.003 (F) 0.003 (F,C) <MDL

Herbicide

2,4-D 0.07 (F) 0.07 (F,N) <MDL

2,4,5-TP (Silvex) L 0.07 (F,N) <MDL

Data source: Centennial Water and Sanitation District, 1998

 Primary maximum contaminant level (MCL), unless otherwise noted. 1

 Primary MCL established for total xylenes. 2

 Health advisory level established for total xylenes. 3 

Regulatory Status:

F Final P Proposed

D Draft R Under Review

L Listed for regulation T Tentative (not officially proposed)

Health Advisory:

C 10 cancer risk N Noncancer lifetime -4

<MDL Less than method detection level.

N/A Not applicable.

i Exceeds primary drinking water standard.
September 30, 1999 20

Table 7. Injectate Data for ASR System in City of Salem, Oregon

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Concentration 1

indicated) indicated) indicated)

Organics

Benzene 0.005 (F) 0.1 (F,C) <MDL

Carbon Tetrachloride 0.005 (F) 0.03 (F,C) <MDL

Chlorobenzene N/A N/A <MDL

1,2-Dichlorobenzene 0.6 (F) 0.6 (F,N) <MDL

1,4-Dichlorobenzene 0.075 (F) 0.075 (F,N) <MDL

1,2-Dichloroethane 0.005 (F) 0.04 (F,C) <MDL

1,1-Dichloroethylene 0.007 (F) 0.007 (F,N) <MDL

cis-1,2-Dichloroethylene 0.07 (F) 0.07 (F,N) <MDL

trans-1,2-Dichloroethylene 0.1 (F) 0.1 (F,N) <MDL

Dichloromethane (Methylene Chloride) 0.005 (F) 0.5 (F,C) <MDL

1,2-Dichloropropane 0.005 (F) 0.06 (F,C) <MDL

Ethylbenzene 0.7 (F) 0.7 (F,N) <MDL

Styrene 0.1 (F) 0.1 (F,N) <MDL

Tetrachloroethylene 0.005 (F) 0.07 (F,C) <MDL

Toluene 1 (F) 1 (F,N) <MDL

1,2,4-Trichlorobenzene 0.07 (F) 0.07 (F,N) <MDL

1,1,1-Trichloroethane 0.2 (F) 0.2 (F,N) <MDL

1,1,2-Trichloroethane 0.005 (F) 0.003 (F,N) <MDL

Trichloroethylene 0.005 (F) 0.3 (F,C) <MDL

Vinyl Chloride 0.002 (F) 0.0015 (F,C) <MDL

Xylenes 10 (F) 10 (F,N) <MDL

Bromobenzene L D <MDL

Bromodichloromethane 0.1 (P) 0.06 (D,N) <MDL

Bromoform 0.1 (P) 0.4 (D,C) <MDL

Bromomethane T 0.01 (D,N) <MDL
Table 7. Injectate Data for ASR System in City of Salem, Oregon (continued)

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Concentration 1

indicated) indicated) indicated)

September 30, 1999 21

Chloroethane L D <MDL

Chloroform 0.1 (P) 0.6 (D,C) 0.011

Chloromethane L 0.003 (F,N) <MDL

2,4-D 0.07 (F) 0.07 (F,N) <MDL

Silvex (2,4,5-TP) 0.05 (F) 0.05 (F,N) <MDL

Aldrin N/A 0.0002 (D,C) <MDL

Chlordane 0.002 (F) 0.003 (F,C) <MDL

Dieldrin N/A 0.0002 (F,C) <MDL

Endrin 0.002 (F) 0.002 (F,N) <MDL

Heptachlor 0.0004 (F) 0.0008 (F,C) <MDL

Heptachlor Epoxide 0.0002 (F) 0.0004 (F,C) <MDL

Lindane 0.0002 (F) 0.0002 (F,N) <MDL

Methoxychlor 0.04 (F) 0.04 (F,N) <MDL

Toxaphene 0.003 (F) 0.003 (F,C) <MDL

Inorganics

Antimony 0.006 (F) 0.003 (F,N) <MDL

Arsenic 0.05 (R) 0.002 (D,C) <MDL

Barium 2 (F) 2 (F,N) 0.0011

Beryllium 0.004 (F) 0.0008 (D,C) <MDL

Cadmium 0.005 (F) 0.005 (F,N) <MDL

Calcium N/A N/A 3.6

Chloride Secondary MCL: 250 (F) N/A 2.3

Chromium 0.1 (F) 0.1 (F,N) <MDL

Copper 1.3 (action level, at tap) (F) N/A 0.01

Secondary MCL: 1 (F)

Fluoride 4 (F,R) N/A 0.8

Secondary MCL: 2 (F)

Iron Secondary MCL: 0.3 (F) N/A <MDL
Table 7. Injectate Data for ASR System in City of Salem, Oregon (continued)

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Concentration 1

indicated) indicated) indicated)

September 30, 1999 22

Lead 0.015 (action level, at tap) (F) N/A 0.0003

Magnesium N/A N/A 1.1

Manganese L N/A 0.0005

Secondary MCL: 0.05 (F)

Mercury 0.002 (F) 0.002 (F,N) <MDL

Nickel 0.1 (F) 0.1 (F,N) <MDL 2

Nitrate, as N 10 (F) N/A 0.04

Potassium N/A N/A 0.5

Selenium 0.05 (F) N/A <MDL

Silica N/A N/A 13

Silver Secondary MCL: 0.1 (F) 0.1 (D,N) <MDL

Sodium N/A D 3

Sulfate 500 (P) D 0.8

Secondary MCL: 250 (F)

Zinc L 2 (D,N) <MDL

Secondary MCL: 5 (F)

Radionuclides

Gross Beta, as CS-137 4 mrem/y (27.7 pCi/l) (F) 4 mrem/y (27.7 pCi/l) (C) <MDL

Gross Beta, as SR/YT-90 4 mrem/y (27.7 pCi/l) (F) 4 mrem/y (27.7 pCi/l) (C) <MDL

Radium 226/228 Combined Radium 226 and Combined Radium 226 <MDL

228: 5 pCi/l (F) and 228: 20 pCi/l (C)

Uranium 0.02 mg/l (P) R 0.000004 mg/l

Microbiological Data

Total Coliform 5/100 ml N/A Absent

E. Coli 5/100 ml N/A Absent
Table 7. Injectate Data for ASR System in City of Salem, Oregon (continued)

Parameter (mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

Drinking Water Standard Health Advisory Level Concentration 1

indicated) indicated) indicated)

September 30, 1999 23

Other Parameters

Alkalinity N/A N/A 15

Conductivity N/A N/A 44 uhmos/cm

Hardness N/A N/A 14

pH Secondary MCL: 6.5 - 8.5 N/A 7.02

Total Dissolved Solids Secondary MCL: 500 (F) N/A 25

Turbidity N/A N/A 0.27 NTU

Data Sources: City of Salem, 1999

 Primary maximum contaminant level (MCL), unless otherwise noted. 1

 Being remanded. 2

Regulatory Status:

F Final D Draft

L Listed for regulation P Proposed

R Under Review T Tentative (not officially proposed)

Health Advisory:

C 10 cancer risk N Noncancer lifetime -4

<MDL Less than method detection level.

 N/A Not available.
September 30, 1999 24

Table 8. Injectate Data for the ASR System 

Operated by the Memphis Light, Gas, and Water Division in Tennessee

Parameter Drinking Water Standard Health Advisory Level Concentration 1

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

Volatile Organic Chemicals

Benzene 0.005 (F) 0.1 (F,C) <MDL

Bromodichloromethane 0.1 (P) 0.06 (D,N) 0.001

Bromoform 0.1 (P) 0.4 (D,C) 0.0005

Carbon Tetrachloride 0.005 (F) 0.03 (F,C) <MDL

Chloroform 0.1 (P) 0.6 (D,C) 0.0008

Dibromochloromethane 0.1 (P) 0.06 (D,N) 0.0075 - 0.029

Dibromochloropropane 0.0002 (F) 0.003 (F,C) <MDL

1,2-Dibromoethane N/A N/A <MDL

o-Dichlorobenzene (1,2-Dichlorobenzene) 0.6 (F) 0.6 (F,N) <MDL

p-Dichlorobenzene (1,4-Dichlorobenzene) 0.075 (F) 0.075 (F,N) <MDL

1,1-Dichloroethane N/A N/A <MDL

1,2-Dichloroethane 0.005 (F) 0.04 (F,C) <MDL

1,1-Dichloroethylene 0.007 (F) 0.007 (F,N) <MDL

cis-1,2-Dichloroethylene 0.07 (F) 0.07 (F,N) <MDL

trans-1,2-Dichloroethylene 0.1 (F) 0.1 (F,N) <MDL

Dichloromethane (Methylene Chloride) 0.005 (F) 0.5 (F,C) <MDL

1,2-Dichloropropane 0.005 (F) 0.06 (F,C) <MDL

Ethylbenzene 0.7 (F) 0.7 (F,N) <MDL

Monochlorobenzene 0.1 (F) 0.1 (F,N) <MDL

Styrene 0.1 (F) 0.1 (F,N) <MDL

1,1,1,2-Tetrachloroethane L 0.07 (F,N) <MDL

0.1 (F,C)

1,1,2,2-Tetrachloroethane L D <MDL

Tetrachloroethylene 0.005 (F) 0.07 (F,C) <MDL

Toluene 1 (F) 1 (F,N) <MDL

1,2,3-Trichlorobenzene N/A N/A <MDL
Table 8. Injectate Data for the Aquifer Storage and Recovery System 

Operated by the Memphis Light, Gas, and Water Division in Tennessee (continued)

Parameter Drinking Water Standard Health Advisory Level Concentration 1

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

September 30, 1999 25

1,2,4-Trichlorobenzene 0.07 (F) 0.07 (F,N) <MDL

1,1,1-Trichloroethane 0.2 (F) 0.2 (F,N) <MDL

1,1,2-Trichloroethane 0.005 (F) 0.003 (F,N) <MDL

Trichloroethylene 0.005 (F) 0.3 (F,C) <MDL

1,2,3-Trichloropropane L 0.04 (F,N) <MDL

0.5 (F,C)

1,2,4-Trimethylbenzene N/A D <MDL

Vinyl Chloride 0.002 (F) 0.0015 (F,C) <MDL

Xylenes 10 (F) 10 (F,N) <MDL

Inorganics

Antimony 0.006 (F) 0.003 (F,N) <MDL

Arsenic 0.05 (R) 0.002 (D,C) <MDL

Barium 2 (F) 2 (F,N) 0.042

Beryllium 0.004 (F) 0.0008 (D,C) <MDL

Cadmium 0.005 (F) 0.005 (F,N) <MDL

Carbon Dioxide N/A N/A 12

Chloride Secondary MCL: 250 (F) N/A 4.9

Chromium 0.1 (F) 0.1 (F,N) <MDL

Copper 1.3 (action level, at tap) (F) N/A <MDL

Secondary MCL: 1 (F)

Fluoride 4 (F,R) N/A 0.96

Secondary MCL: 2 (F)

Iron Secondary MCL: 0.3 (F) N/A 0.04

Lead 0.015 (action level, at tap) (F) N/A <MDL

Manganese L N/A 0.004

Secondary MCL: 0.05 (F)

Mercury 0.002 (F) 0.002 (F,N) <MDL

Molybdenum L 0.04 (D,N) <MDL

Nickel 0.1 (F) 0.1 (F,N) <MDL 2

Nitrate (as N) 10 (F) N/A 0.9
Table 8. Injectate Data for the Aquifer Storage and Recovery System 

Operated by the Memphis Light, Gas, and Water Division in Tennessee (continued)

Parameter Drinking Water Standard Health Advisory Level Concentration 1

(mg/l, unless otherwise (mg/l, unless otherwise (mg/l, unless otherwise

indicated) indicated) indicated)

September 30, 1999 26

Phosphate N/A N/A 1

Selenium 0.05 (F) N/A <MDL

Silica N/A N/A 13.8

Sulfate 500 (P) D 3.6

Secondary MCL: 250 (F)

Thallium 0.002 (F) 0.0005 (F,N) <MDL

Zinc L 2 (D,N) <MDL 

Secondary MCL: 5 (F)

Other Parameters

Alkalinity N/A N/A 54

Conductivity N/A N/A 133.2 uhmos

Dissolved Oxygen N/A N/A 8.4

Hardness N/A N/A 49

pH Secondary MCL: 6.5 - 8.5 N/A 7.08

Temperature N/A N/A 20.6

Total Dissolved Solids Secondary MCL: 500 (F) N/A 77

Data source: MGLWD, 1997

 Primary maximum contaminant level (MCL), unless otherwise noted. 1

 Being remanded. 2

Regulatory Status:

F Final D Draft

L Listed for regulation P Proposed

R Under Review

Health Advisory:

C 10 cancer risk N Noncancer lifetime -4

<MDL Less than method detection level.

N/A Not applicable.
September 30, 1999 27

4.2 Well Characteristics

4.2.1 Design Features

Although the design and construction of aquifer recharge and ASR wells depend on sitespecific conditions and the intended use of the recharged water after withdrawal (e.g., drinking

water versus agricultural water), the components of most recharge wells are very similar. These

include: (1) the well casing; (2) the well screen (except in rock and other open hole wells); (3)

sand/gravel (filter) pack around the screen (except in rock and other open hole wells); (4)

grout/cement around the casing; and (5) a pump. Figure 1 illustrates a typical recharge well. 

Figure 2 shows schematics of a typical ASR well.

 Figure 1. Typical Recharge Well Figure 2. Typical ASR Well

 

 Source: 

Powers, 1992

 

Source: Pyne, 1995 (ASR well in Marathon, Florida)

 
September 30, 1999 28

Uncoated steel casing is typically used in the construction of injection wells. However,

steel-cased ASR wells are more vulnerable to rusting than most other injection wells because

alternating periods of recharge and recovery during ASR operations expose a large surface area

to frequent wetting and drying. This frequent wetting and drying causes rust to form on the

inside of the well. During recharge periods, the rust becomes suspended in injection water with

other solids and contributes to well clogging. To avoid this problem, ASR wells may be

constructed using material that will not contribute to the production of rust—in particular,

polyvinyl chloride (PVC). However, if steel casing is required, epoxy coating can substantially

reduce the surface area of steel subject to rusting. These two approaches have been proven to be

successful in operational ASR systems. Other materials that could be used in the construction of

ASR well casings are fiberglass and stainless steel, but they are more expensive alternatives. 

One example of the use of stainless steel in the construction of ASR wells is a well in the city of

Delray Beach, Florida. That ASR well has a type 316 stainless steel final casing to protect

against electrolysis. 

In an ASR system, the proper selection of the pumping equipment is of prime importance

because the same well-pump combination will be used for recharge and recovery purposes. 

Submersible pumps are often used in ASR wells for recovery of stored water. Conventionally,

ASR systems place the pump at the base of the casing, above the well screen. While this design

has been successful in the past, a new design alternative has been suggested. In this alternative,

the pump is placed below the screen interval at the bottom of the well. Figure 3 shows the two

design options. 

Figure 3. Alternative Pump Setting for ASR Wells

Source: Pyne, 1995
September 30, 1999 29

It should be noted that the above description covers the most common well design. 

However, wells could be constructed using other designs, such as slant or horizontal casings or

multiple casings nested on a single bore hole to control injection into specific aquifer zones.

4.2.2 Siting Considerations

There are several factors that are common to the site selection process of all aquifer

recharge and ASR wells. These include physical siting criteria, recharge water availability and

quality, water demand (if applicable), regulatory and institutional issues, and economic

considerations. A discussion of each of these factors follows.

Physical Siting Criteria

Under ideal conditions a well will accept recharge water at least as readily as it will yield

water by pumping. However, actual conditions are never ideal. For that reason, it is common to

conduct a hydrogeologic evaluation of the area. This evaluation provides the information

necessary to select suitable storage zones, recharge water sources, and treatment requirements (if

any). These hydrogeologic characteristics affect the location and design of the wells and have to

be considered for a successful recharge project.

The hydrogeologic evaluation considers the following factors:

1. availability of an aquifer suitable for recharge;

2. aquifer areal extent, thickness, and depth;

3. geologic structure (unconsolidated, consolidated, fractures, bedding planes,

fissures, etc.);

4. hydraulic characteristics (transmissivity, storativity, hydraulic conductivity,

porosity, etc.);

5. mineralogy of clays, sands, and other soil components;

6. confining layers or aquitards (areal extent, thickness, and depth);

7. lithology of aquifer and confining layers;

8. chemical characteristics of the native ground water;

9. native ground water velocity and direction;

10. water table levels or potentiometric surface;

11. local gradient of the potentiometric surface;

12. geochemical compatibility of recharge and native water with formation minerals;

13. proximity of the potential recharge site to an appropriate well field cone of

depression;

14. water level differences between the aquifer and the recharge site;

15. topography;

16. well inventory within a reasonable radius;

17. ground water withdrawals within the surrounding area;

18. proximity of potential sources of contamination; and

19. proximity of potential contamination plumes that may be affected by recharge

operations (O’Hare, 1986).
September 30, 1999 30

In addition, delineated wellhead protection and source water protection areas should be taken

into consideration for the siting of the wells.

In short, there are many hydrogeologic characteristics to be considered when determining

if a particular site will be suitable for artificial recharge through recharge wells. After all

applicable data are obtained, computer simulation modeling of the proposed recharge may be

necessary and appropriate if there are any special concerns. Results of these analyses would be

useful in deciding the location and design of the recharge wells.

Water Availability and Quality

The availability and quality of a source of water for artificial recharge also is an

important factor in site selection. Many geographical areas that have demonstrated needs and

many sites that are physically suitable for artificial recharge can never be developed due to lack

of an acceptable water source. The types of water that may be considered for artificial recharge

vary with the locality. 

For water to qualify for consideration as a source water for artificial recharge, the

chemical, physical, and biological characteristics are evaluated relative to the native water

characteristics. This evaluation provides the information necessary to understand the interaction

between the recharge and the native water, establish the criteria for the quality of the recharge

water to prevent degradation in the quality of the native ground water, and determine if treatment

of the recharge water is necessary. 

Water Demand

If artificial recharge is used primarily as a water resource management tool, evaluation of

water demands, including average demands, monthly variability, and trends is important in order

to assess the duration of peak demand periods when recovery of stored water would provide

maximum benefit. 

Regulatory and Institutional Issues

Regulatory and institutional issues are also considered in artificial recharge site selection.

These are particularly important because each state has its own requirements and procedures, as

discussed in Section 7. In addition, the federal government (U.S. Bureau of Reclamation and

U.S. Geological Survey) is involved in recharge activities through funding of local

demonstration programs and state water projects, and USEPA or state UIC Primacy Programs

have a say as part of their particular Class V programs. In some instances, consideration of local

perspectives and relationships is also necessary.
September 30, 1999 31

Economic Considerations

Any proposed artificial recharge project first has to be evaluated relative to its

effectiveness and economic justification. Thus, a preliminary estimate of the capital and

operating cost of injection well operations is usually developed. Such analysis considers the

useful life of the recharge project and the anticipated future availability of the recharge water

source.

4.3 Operational Practices

As stated earlier, a recharge well may be defined as a well that is used to inject water

(from the surface) to replenish the water in a fresh water aquifer. When water is injected into a

recharge well, a mound in the potentiometric surface of a confined aquifer, or the water table of

an unconfined aquifer, is created. The mound extends unsymmetrically in the direction of the

regional flow in the aquifer. As injection continues, the areal extent of the mound spreads to

occupy an ever-increasing area (Freeze and Cherry, 1979). This process forms a cone of

recharge that is similar in shape but the reverse of a cone of depression surrounding a pumping

well. Thus, this process may be viewed as the inverse of the effect of a pumping well in a

confined aquifer, and, in fact, is described mathematically by the same equations, modified for

the effect of injection rather than pumping (Warner, 1965). Additional information on this topic

might be found in sources such as Driscoll (1986), O'Hare et al. (1986), and Todd (1980).

A number of factors affect recharge performance. Most of the problems in recharging

through wells, especially in aquifers composed of fine-grained material, involve excessive

buildup of water levels in the recharge well because of clogging of the well screen or aquifer.

Injecting high-quality water reduces the frequency of well clogging, increases the operating life

of the well, and reduces cleaning costs. In addition, chlorination of the injected water helps to

protect the well casing, prevents potential leaks, and reduces nearfield biofouling of the

formations (Bloetscher, 1999). However, even when using high-quality water, clogging is

inevitable. 

When there is clogging and the injection head has increased above acceptable levels

(approximately every three years when using high-quality injectate water), redevelopment of the

injection wells is necessary (Bruington, 1968). Redevelopment of a well involves the removal of

finer material from the natural formations surrounding the perforated sections of the casing. 

Periodic redevelopment of the well is used to restore its efficiency and specific capacity. 

Thorough initial development of the injection wells will delay the need for redevelopment and

increase the initial specific capacity of the well, making it more efficient (Bruington, 1968).

Calibration of flow meters and other equipment associated with the recharge well system

is another standard operating procedure. Calibration is important to accurately keep track of

flow rates in order to determine whether clogging is occurring and whether redevelopment is

necessary. 

A key factor in the operation of an ASR well is its recovery efficiency. Recovery

efficiency is defined as the percentage of the water volume stored that is subsequently recovered
September 30, 1999 32

while meeting a target water quality criterion in the recovered water (Pyne, 1995). According to

Pyne (1995), recovery efficiency tends to improve with successive cycles when the same volume

of water is stored in each cycle because the residual water not recovered in one cycle becomes a

transition or buffer zone of marginal quality surrounding the stored water in the next cycle. 

Building the buffer zone around each ASR well is usually completed over a series of cycles,

typically about three to six, at the end of which the ultimate recovery efficiency for the site is

achieved.

One ASR cycle consists of three different operating phases: injection, storage, and

subsequent recovery of potable water. During the first phase, water is injected into an aquifer

when excess runoff or excess water supplies from a treatment plant are available for storage. 

During the second operating phase, potable water is stored in an aquifer. Storage times are

typically diurnal, long-term (injected during wet years then recovered in dry years), or seasonal

(injected during the fall and winter then recovered in the spring and summer). Water may also

be stored for emergency use during drought or flooding. The last part of the cycle is recovery. 

Recovered water is used for drinking water, irrigation, and other agricultural purposes.

5. POTENTIAL AND DOCUMENTED DAMAGE TO USDWs

5.1 Injectate Constituent Properties

As discussed in Section 4.1, water injected into aquifers through the use of aquifer

recharge and ASR wells is typically treated to meet primary and secondary drinking water

standards. This is done to protect the host aquifer and to help ensure that the quality of the

ground water to be recovered is adequate for subsequent use. In addition, treatment of the

injectate in aquifer recharge and ASR wells to drinking water standards is required by most

regulatory agencies in order to prevent degradation of ambient ground water quality (see Section

7). However, not all fluids injected into aquifer recharge and ASR wells meet drinking water

standards. Injection of fluids with chemical concentrations can be allowed as long as it is found

not to endanger USDWs. Thus, aquifer recharge and ASR wells injecting fluids that do not meet

drinking water standards can still have an environmental benefit.

It should be noted that, even when water injected into aquifers through the use of aquifer

recharge and ASR wells has been treated, a few constituents have been measured at

concentrations slightly above drinking water standards. For example, fluoride concentrations in

the recharge water used in the Huron Project in South Dakota (see Section 4.1.1) and combined

radium 226 and 228 concentrations at Centennial Water and Sanitation District in Denver,

Colorado (see Section 4.1.2) have been observed slightly above the drinking water standards. 
September 30, 1999 33

5.2 Observed Impacts

The objective of aquifer recharge and ASR wells is to replenish water in an aquifer for

subsequent use. Thus, aquifer recharge and ASR wells are closely controlled to make sure they

safely augment the amount of water available from a USDW. These controls make hazardous

material spills or illicit discharges into aquifer recharge and ASR wells unlikely.

Based on information obtained from state and USEPA Regional offices, there are no

known contamination incidents associated with the use of aquifer recharge and ASR wells. 

However, changes in water quality of the aquifers have been observed. In addition, in some

instances, injection of high quality water into aquifers that contain either brackish or poor quality

water has improved the ambient ground water quality.

6. BEST MANAGEMENT PRACTICES

6.1 Aquifer Recharge and ASR Wells

6.1.1 Recharge Water Quality

In order to ensure the use of “good” quality recharge water, monitoring of recharge water

quality should be performed on a routine basis. If the recharge water is not low in suspended

solids, air, and microorganisms, and is not chemically compatible with natural ground water and

the aquifer material, clogging can cause a recharge operation to be infeasible (Lichtler et al.,

1980). 

The intended use or recharge objective needs to be considered in evaluating the quality of

the recharge water. For example, if artificial recharge is going to be used primarily for water

storage, it is necessary to consider changes that may take place between the time of recharge and

the time of withdrawal and use by the consumer. The following basic processes must be

considered when evaluating water quality changes likely to occur during ground water recharge

and storage:

1. biodegradation by and growth of microorganisms;

2. chemical oxidation or reduction;

3. sorption and ion exchange;

4. filtration;

5. chemical precipitation or dilution; and

6. volatization or photochemical reactions.

In addition, a contaminant source inventory in the area supplying the injectate water

should be conducted in order to prevent potential contamination of the receiving aquifer.

 
September 30, 1999 34

6.1.2 Water Monitoring in Recharge Projects

Monitoring of ground water is necessary to ascertain the direction and rate of movement

of water and the extent of water quality changes occurring during movement of the recharged

water through the aquifer. As a result, a monitoring plan is needed to properly assess and

minimize the water quality impacts of an aquifer recharge project. A monitoring plan should

take into account several conditions, including:

C The nature of the hydrogeologic and hydrochemical setting;

C An analysis of the source of the recharge water;

C A determination of the constituents that may be contributed by the source; and

C An assessment of potential aquifer-plugging mechanisms (Shea-Albin, 1997).

Initially, ground water and recharge water should be monitored for all analytes for which

drinking water standards have been promulgated and for all potential contaminants in the source

water contribution area. It is important to analyze for all of these contaminants during the

baseline sampling period, even if a particular aquifer may not be vulnerable to contamination. If

contaminants of concern are not present in baseline samples, reduction in future monitoring

requirements may be possible (Shea-Albin, 1997).

6.1.3 Physical, Biological, Chemical, and Mechanical Clogging

Understanding the interaction between the recharge and native water will prevent

clogging of the well, which is one of the major operational problems with recharge injection

wells. Factors that may contribute to clogging of the well include:

1. suspended sediment in the recharge water (including both organic and inorganic

matter);

2. entrained air in the recharge water;

3. microbial growth in a well;

4. chemical reactions between recharge water and the native ground water, the

aquifer material, or both;

5. ionic reactions that result in dispersion of clay particles and swelling of colloids

in a sand-and-gravel aquifer;

6. iron precipitation;

7. biochemical changes in the recharge water and ground water involving ironreducing bacteria or sulfate-reducing organisms; and

8. differences in temperature between recharge and aquifer water (Pyne 1995;

Sniegocki, 1970).

The following sections describe the most common types of clogging problems and

presents methods for the early detection and prevention of problems associated with physical,

biological, chemical, and mechanical clogging problems.
September 30, 1999 35

Physical Clogging

Physical clogging problems result from suspended solids clogging the pores of the

receiving formation, well screens, and/or gravel packs. This type of clogging is more prevalent

in raw water recharge systems than in treated water systems because treated water will have few,

if any, suspended solids. The particles settle around the recharge well, creating a need for higher

injection pressures. 

For ASR wells, backflushing, or reversing the flow of the wells for recovery operations,

may alleviate physical clogging problems. The amount of time a well should be backflushed is

site dependent. Some ASR wells are backflushed every day for 10 minutes to 2 hours, while

others are backflushed every few weeks for varied durations. The waste from backflushing is

sometimes routed to a water treatment plant for re-treatment before disposal to a drainage field,

storm drain, dry well, pit, pond, or sewer system. 

Physical clogging problems can also be the result of temperature differences between the

injectate and the receiving waters. When cold injection water comes into contact with warm

aquifer water, outgassing (formation of gas bubbles in the injectate) may occur. The dissolved

gases in the injection water tend to escape out of solution and clog the aquifer. Outgassing due

to temperature differentials may be prevented by studying the changes in water temperature and

the mixing characteristics of the injectate and the receiving water (Pitt and Magenheimer, 1997). 

Cold water also tends to have a higher viscosity than warm water, which may reduce flow rates. 

The probability of clogging due to temperature differentials is highly site specific. Typically,

temperature differentials are more likely to occur with the first injection cycle. The cold

injectate displaces the receiving water around the borehole, and after the first injection cycle,

little temperature difference is found. 

Biological Clogging

Recharge wells are sometimes clogged by bacterial growth. Pre-chlorination of the

injection water may solve the problem. For raw surface water or non-potable recharge systems,

adding chlorine to the injection water will reduce well clogging. 

Chemical Clogging

Chemical clogging problems can be caused by precipitates, clay colloids, gas bubbles,

and protective chemicals (Pitt and Magenheimer, 1997). These problems may arise from

geochemical reactions between native ground water and the injectate (Pitt and Magenheimer,

1997). For example, formation of chemical precipitates (usually calcium carbonate, calcium

sulphate, iron oxides, manganese oxides, magnesium hydroxide, and silicates) may arise as a

result of reactions between native ground water and recharge water. These precipitates can clog

the well screen, the gravel pack, or the formation. 

Carbonate precipitation can be controlled by lowering the pH of injection water. If

extensive precipitation has already occurred, acidizing the well with a corrosion inhibitor

dissolves the precipitates and prevents further corrosion of the steel casing. Injection of liquid
September 30, 1999 36

and gaseous carbon dioxide through the packer into the well screen will also remediate clogging. 

In this process, the gas expands, forms carbonic acid, and then freezes in the well screen. After a

few days, the particles dissolve and pH values decrease (Pitt and Magenheimer, 1997). 

Thin clay layers in the storage zone may swell and plug the formations around the zone. 

Clay colloids (particles) may also break free, travel as suspended solids, and clog the pores of the

receiving formation. Injection waters containing high sodium concentrations may exacerbate

clogging by hydrating the clay, thereby causing the clay to swell, potentially clogging the well

and the aquifer. Examining the well construction report and geological data will determine

whether or not clogging problems from clay colloids or thin clay layers in the injection zone can

be expected. Remedial measures include adding chemical stabilizers to the injection water to

reduce clay swelling and treating the injection water to remove sodium. 

Outgassing from the injection water may also cause well clogging. In this case, an

analysis of dissolved gases in the injection water should determine the degree of gas saturation. 

If the concentration of dissolved gases in injection water is likely to cause a well clogging

problem, the water can be treated with degasification through a stripping column. 

Sometimes chemicals such as anti-scalants, which are added to the injectate to protect

pipelines in the distribution system, precipitate and contribute to aquifer clogging. Through

chemical reactions, these chemicals dissolve, loosen, and re-suspend sediments in the pipelines

and encourage bacterial growth (Pitt and Magenheimer, 1997). Using anti-scalants that degrade

during transport from the treatment plant to the injection well (e.g., zinc pyrophosphate) will

decrease the potential for well and aquifer clogging. For example, zinc pyrophosphate will not

loosen and re-suspend bacteria and other solids in the pipelines because it degrades during

transport. Well clogging due to anti-scalant chemicals may also be averted by performing a

complete investigation of the chemicals used in the water treatment process. Assessing the

potential chemical reactions between recharge water, pipeline materials, and anti-scalant

chemicals will alert recharge managers to potential well clogging problems, so that clogging may

be avoided or treated before serious problems occur. 

Mechanical Clogging

For ASR wells, there are some potential problems that may be caused by mechanical

clogging. Mechanical clogging problems include air entrainment and formation particle

jamming (Pitt and Magenheimer, 1997). Air entrainment, one type of air clogging, traps

atmospheric air in the ASR well and in the storage zone during the storage cycle. This may

occur when the injection water has a lower temperature than native ground water, clogging the

aquifer. Sealing the annulus at the well head typically prevents air entrainment during ASR

operations. Air entrainment can be tested by conducting a mechanical integrity test (Pyne,

1995). Air entrainment is not equivalent to outgassing, although temperature differentials may

cause outgassing and add to aquifer clogging problems. Other common causes of air clogging

include loose connections in piping, the use of inadequate pumps, cavitation of the injection

pump (air in the pump), and high injection velocities. These problems may best be addressed by

maintaining airtight pipelines and connections, using centrifugal pumps, and ensuring that
September 30, 1999 37

injection velocities are kept at a level below that which causes turbulent flow. Pump cavitation

should not occur during injection (Pitt and Magenheimer, 1997).

Aquifer jamming may result from particle displacement when water flow in the ASR

system is reversed from the injection to the recovery cycle. This problem is only encountered in

loosely consolidated aquifers and when the well is gravel-packed with gravel/particles of

relatively uniform size. When the water flow is reversed, the particles are drawn back toward

the well, and their packing is rearranged. This reduces water flow efficiency and has the same

effect on the ASR system as particulate clogging. To remediate aquifer jamming, the wells may

need to be redeveloped by surging and pumping methods or by acidizing. Pressure fracturing or

explosive fracturing, where the aquifer is broken apart by extreme physical or explosive force,

will also dislodge the jammed aquifer but may not be permitted in every state. Maintaining low

velocities during the recovery cycle and ensuring that the screen and gravel pack match the

aquifer materials can reduce the risk of aquifer jamming (Pitt and Magenheimer, 1997).

6.2 ASR Wells

6.2.1 Location and Spacing of ASR Wells and Impact on Static Ground Water Levels

The long-term and regional effects of ASR cycles need to be considered when

configuring ASR systems. Therefore, developing optimal water basin management strategies is

important (Dickenson, 1997). Background basin hydrology, including natural recharge sources

and locations, pumping patterns, discharge areas, and the proposed storage area, should be

examined. Spilling and overdraft patterns (patterns where the water table and/or aquifer level is

too high or too low) in the proposed ASR area should be assessed so that ASR injection and

recovery operations dampen extreme fluctuations in ground water levels, rather than exacerbate

existing problems. Pyne (1995) suggests that ASR facilities be located near water treatment

plants and at least 100 feet from existing or potential sources of contamination. He also points

out that this siting criterion is a regulatory requirement in some states.

6.2.2 Operation and Maintenance Practices for ASR Wells

In order to successfully operate an ASR system, the following operation and maintenance

practices, as described by Pyne (1995), are recommended:

C Periodic change in operating mode. This occurs typically two to four times per year as

the system changes from recharge to recovery and back again.

C Backflushing to waste during recharge. This procedure is implemented at most ASR

sites in order to maintain recharge capacity by purging from the well any solids that may

have been carried into the well during recharge. Backflushing frequency varies from

every day to every few years, depending on site-specific conditions. Some ASR wells

currently in operation are redeveloped seasonally by extended pumping, as part of the

recovery operation, without any additional backflushing frequency.
September 30, 1999 38

C Trickle flow of chlorinated water. During periods of storage, it is advisable to maintain a

trickle flow of chlorinated water into the well. This will control bacterial activity in the

formation immediately adjacent to the well, thereby helping to maintain recharge-specific

capacity and bacterial clogging. 

C Calibration of pressure gauges, flow meters, chart recorders, and other equipment

associated with the ASR well system. It is important to accurately keep track of flow

rates and pressure and water levels in order to determine whether clogging is occurring

and backflushing is necessary. 

C Monitoring. Monitoring of ground water during recharge, storage, and recovery is

necessary to ascertain the direction and rate of movement of water and the extent of water

quality changes occurring during movement of the recharged water through the aquifer. 

C Annual water accounting or water balance. It is important to accurately track the

volume of water stored and recovered from an ASR well system. If the volume of water

recovered is greater than the volume of the water stored, there might be a reduction in the

recovery efficiency around the well, as well as adverse impacts on water levels in

surrounding areas. In addition, ASR permits are sometimes issued providing only for

seasonal storage and recovery, so that annual volume recovered cannot exceed the

volume stored in the same year (Pyne, 1995).

C Periodic review of operating and water quality data. This review is necessary in order to

evaluate performance relative to expectations, and make adjustments, as appropriate. 

This is particularly important in the first two to five years of system operation, when the

greatest changes in water levels and water quality will tend to occur and normal ranges

for various parameters tend to be defined.

7. CURRENT REGULATORY REQUIREMENTS

Several federal, state, and local programs exist that either directly manage or regulate

Class V aquifer recharge and ASR wells. On the federal level, management and regulation of

these wells falls primarily under the UIC program authorized by the Safe Drinking Water Act

(SDWA). Some states and localities have used these authorities, as well as their own authorities,

to extend the controls in their areas to address concerns associated with aquifer recharge and

ASR wells.

7.1 Federal Programs

7.1.1 SDWA

Class V wells are regulated under the authority of Part C of SDWA. Congress enacted

the SDWA to ensure protection of the quality of drinking water in the United States, and Part C

specifically mandates the regulation of underground injection of fluids through wells. USEPA

has promulgated a series of UIC regulations under this authority. USEPA directly implements
September 30, 1999 39

these regulations for Class V wells in 19 states or territories (Alaska, American Samoa, Arizona,

California, Colorado, Hawaii, Indiana, Iowa, Kentucky, Michigan, Minnesota, Montana, New

York, Pennsylvania, South Dakota, Tennessee, Virginia, Virgin Islands, and Washington, DC). 

USEPA also directly implements all Class V UIC programs on Tribal lands. In all other states,

which are called Primacy States, state agencies implement the Class V UIC program, with

primary enforcement responsibility.

Aquifer recharge and ASR wells currently are not subject to any specific regulations

tailored just for them, but rather are subject to the UIC regulations that exist for all Class V

wells. Under 40 CFR 144.12(a), owners or operators of all injection wells, including aquifer

recharge and ASR wells, are prohibited from engaging in any injection activity that allows the

movement of fluids containing any contaminant into USDWs, “if the presence of that

contaminant may cause a violation of any primary drinking water regulation . . . or may

otherwise adversely affect the health of persons.” 

Owners or operators of Class V wells are required to submit basic inventory information

under 40 CFR 144.26. When the owner or operator submits inventory information and is

operating the well such that a USDW is not endangered, the operation of the Class V well is

authorized by rule. Moreover, under section 144.27, USEPA may require owners or operators of

any Class V well, in USEPA-administered programs, to submit additional information deemed

necessary to protect USDWs. Owners or operators who fail to submit the information required

under sections 144.26 and 144.27 are prohibited from using their wells.

Sections 144.12(c) and (d) prescribe mandatory and discretionary actions to be taken by

the UIC Program Director if a Class V well is not in compliance with section 144.12(a). 

Specifically, the Director must choose between requiring the injector to apply for an individual

permit, ordering such action as closure of the well to prevent endangerment, or taking an

enforcement action. Because aquifer recharge and ASR wells (like other kinds of Class V wells)

are authorized by rule, they do not have to obtain a permit unless required to do so by the UIC

Program Director under 40 CFR 144.25. Authorization by rule terminates upon the effective

date of a permit issued or upon proper closure of the well. 

Separate from the UIC program, the SDWA Amendments of 1996 establish a

requirement for source water assessments. USEPA published guidance describing how the states

should carry out a source water assessment program within the state’s boundaries. The final

guidance, entitled Source Water Assessment and Programs Guidance (USEPA 816-R-97-009),

was released in August 1997.

State staff must conduct source water assessments that are comprised of three steps. 

First, state staff must delineate the boundaries of the assessment areas in the state from which

one or more public drinking water systems receive supplies of drinking water. In delineating

these areas, state staff must use “all reasonably available hydrogeologic information on the

sources of the supply of drinking water in the state and the water flow, recharge, and discharge

and any other reliable information as the state deems necessary to adequately determine such

areas.” Second, the state staff must identify contaminants of concern, and for those

contaminants, they must inventory significant potential sources of contamination in delineated
May 2003 is the deadline including an 18-month extension. 2

September 30, 1999 40

source water protection areas. Class V wells, including aquifer recharge and ASR wells, should

be considered as part of this source inventory, if present in a given area. Third, the state staff

must “determine the susceptibility of the public water systems in the delineated area to such

contaminants.” State staff should complete all of these steps by May 2003 according to the final

guidance.2

7.1.2 Other Federal Rules and Programs

As stated earlier, aquifer recharge and ASR wells are used to replenish water in an

aquifer. In most cases, aquifer recharge and ASR wells inject water into USDWs. Thus, the

injectate from these wells is typically treated to drinking water standards established under

Section 1412 of the SDWA. This section requires USEPA to establish National Primary

Drinking Water Regulations for a contaminant if (1) the contaminant may have an adverse public

health effect; (2) it is known or likely to occur in public water systems with a frequency and at

levels of public health concern; and (3) if regulation of such contaminant presents a meaningful

opportunity for health risk reduction. A brief description of these regulations follows.

Total Trihalomethane Rule

In November 1979, USEPA set an interim MCL for total trihalomethanes (TTHMs) of

0.10 mg/l as an annual average (44 FR 68624). Compliance is defined on the basis of a running

average of quarterly averages of all samples. The value for each sample is the sum of the

measured concentrations of chloroform, bromodichloromethane, dibromochloromethane, and

bromoform. The interim TTHM standard only applies to community water systems using

surface water and/or ground water serving at least 10,000 people that add a disinfectant to the

drinking water during any part of the treatment process.

Surface Water Treatment Rule

In June 29, 1989, USEPA promulgated the final Surface Water Treatment Rule (SWTR)

(54 FR 27486). Under the SWTR, USEPA set maximum contaminant level goals (MCLGs) of

zero for Giardia lamblia, viruses, and Legionella; and promulgated NPDWRs for all public

water systems using surface water sources or ground water sources under the direct influence of

surface water. The SWTR includes treatment technique requirements for filtered and unfiltered

systems that are intended to protect against the adverse health effects of exposure to Giardia

lamblia, viruses, and Legionella, as well as many other pathogenic organisms. The rule became

effective in June 1993.

Total Coliform Rule

In June 29, 1989, USEPA also promulgated the Total Coliform Rule, which applies to all

public water systems (54 FR 27544). This regulation sets compliance with a MCL for total
September 30, 1999 41

coliforms. If a system exceeds the MCL, it must notify the public using mandatory language

developed by the USEPA.

Interim Enhanced Surface Water Treatment

On December 16, 1998, USEPA finalized the Interim Enhanced Surface Water Treatment

Rule (IESWTR) (63 FR 69478). The purposes of the IESWTR are to: (1) improve control of

microbial pathogens, including specifically protozoan Cryptosporidium, in drinking water; and

(2) address risk trade-offs with disinfection products. The IESWTR applies to public water

systems that use surface or ground water under the direct influence of surface water and serve

10,000 or more people. The regulation became effective on February 16, 1999. 

Stage 1 Disinfection Byproducts Rule

In December 16, 1998, USEPA finalized: (1) maximum residual disinfectant level goals

(MRDLGs) for chlorine, chloramines, and chlorine dioxide; (2) MCLGs for four trihalomethanes

(chloroform, bromodichloromethane, dibromochloromethane, and bromoform), two haloacetic

acids (dichloroacetic acid and trichloroacetic acid), bromate, and chlorite; and (3) NPDWRs for

three disinfectants (chlorine, chloramines, and chlorine dioxide), two groups of organic

disinfection byproducts (TTHMs—a sum of chloroform, bromodichloromethane,

dibromochloromethane, and bromoform—and haloacetic acids—a sum of dichloroacetic acid,

trichloroacetic acid, monochloroacetic acid, and mono-and dibromoacetic acids), and two

inorganic disinfection byproducts (chlorite and bromate) (63 FR 69389). The NPDWRs consist

of maximum residual disinfectant levels or MCLs or treatment techniques for these disinfectants

and their byproducts. The NPDWRs also include monitoring, reporting, and public notification

requirements for these compounds. 

The Stage 1 Disinfection Byproducts Rule applies to public water systems that are

community water systems and nontransient, noncommunity water systems that treat their water

with a chemical disinfectant for either primary or residual treatment. In addition, certain

requirements for chlorine dioxide apply to transient noncommunity water systems.

Radon Rule

On July 18, 1991, USEPA proposed a MCLG, a MCL, monitoring, reporting, and public

notification requirements for radon and a number of other radionuclides in public water supplies

(systems serving 25 or more individuals or with 15 or more connections) (56 FR 33050). 

USEPA proposed to regulate radon at 300 pCi/l. 

On August 6, 1996, Congress passed amendments to the SDWA. Section 1412(b)(13)(A)

of the SDWA, as amended, directs USEPA to withdraw the proposed national primary drinking

water regulation for radon. Thus, as directed by Congress, on August 6, 1997 (62 FR 42221),

USEPA withdrew the 1991 proposed MCLG, MCL, monitoring, reporting, and public

notification requirements for radon. 

USEPA expects to publish a final MCLG and national primary drinking water regulation

for radon by August, 2000.
September 30, 1999 42

Ground Water Rule

Currently, USEPA is developing a Ground Water Rule that will specify appropriate use

of disinfection and encourage the use of alternative approaches, including best management

practices and control of contamination at its source. The rule will be designed to protect against

pathogenic bacteria and viruses in source water, against growth of opportunistic pathogenic

bacteria in ground water distribution systems, and to mitigate against any failure in the

engineered systems, such as cross-connections or sewage infiltration into distribution systems.

The Ground Water Rule will apply to systems using only ground water, which are not regulated

under the 1989 SWTR. 

 USEPA expects to publish the Final Ground Water Rule by November 2000. The

statutory deadline, under the SDWA (Section 1412(b)(8)), for the Ground Water Rule is May

2002.

7.2 State and Local Programs

The requirements pertaining to aquifer recharge and ASR wells in states that contain

substantial numbers of such wells are sometimes identical. In California, for example, both

types of wells are regulated under the state’s Water Quality Control Act. Florida, in contrast, has

enacted specific regulatory requirements for aquifer storage and recovery. Some relatively arid

western states have enacted rules pertaining to aquifer storage and recovery as part of their

system of regulating the use of the water resources of the state, but those requirements also may

touch upon well construction standards and/or monitoring requirements. 

This section summarizes the existing UIC programs in the states where the vast majority

of the aquifer recharge and ASR wells are known to exist: California, Colorado, Florida, Idaho,

Nevada, Oklahoma, Oregon, South Carolina, Texas, and Washington (see Section 3). 

Altogether, these ten states have a total of 1,049 documented aquifer recharge and ASR wells,

which is approximately 89 percent of the documented well inventory for the nation. More detail

on these state programs is provided in Attachment C of this volume.

It should be noted that ASR wells are not specifically defined in 40 CFR Part 146. Thus,

the definition of ASR wells may vary from state to state.

In California, USEPA Region 9 directly implements the UIC program for Class V

injection wells. Aquifer recharge and ASR wells in the state are authorized by rule in

accordance with the existing federal requirements. However, if treated wastewater is planned to

be used for artificial recharge, Regional Water Quality Control Boards issue site-specific

discharge requirements. In addition, the Department of Health Services must review and

approve the application. The injectate must meet drinking water standards at the point of

injection. County water districts and/or county health departments may supplement the

requirements. If potable water is planned to be used for aquifer recharge, the projects are

reviewed and regulated by local health departments.
September 30, 1999 43

In Colorado, USEPA Region 8 directly implements the UIC program for Class V

injection wells. The state does not have rules explicitly addressing ASR wells, but it has enacted

requirements directly addressing artificial recharge. However, those rules apply primarily to the

permitting of extraction and use of waters artificially recharged. The rules do provide that water

artificially recharged into a Denver Basin aquifer, whether for the maintenance of water levels or

for subsequent extraction, shall be, at the time of extraction, fully consumable and/or reusable

(Rule 5.1). In addition, the State Engineer accounts for water that is artificially recharged and

administers the orderly withdrawal of such water to prevent injury to existing water users and

water rights holders.

Florida is a UIC Primacy State for Class V wells. In this state, owners or operators of

aquifer recharge and ASR wells are required to obtain a Construction/Clearance Permit from the

Department of Environmental Protection before receiving permission to construct. In order to

use the well, the applicant is required to submit information needed to demonstrate that well

operation will not adversely affect a USDW. Once such a demonstration is made, the

Department will issue an authorization to use the well subject to certain operating and reporting

requirements, including the requirement to meet drinking water standards at the point of

injection. Injection of fluids that exceed the drinking water standards is allowed only if it is not

into a USDW and if it is controlled in accordance with a site-specific operating permit.

Idaho is a UIC Primacy State for Class V wells. In this state, construction and operation

of shallow injection wells (<18 feet) is authorized by rule, as long as inventory information is

provided and use of the well does not result in endangerment of a drinking water source or cause

a violation of state water quality standards that would affect beneficial use. Construction and use

of a deep injection well ($18 feet) requires an individual permit. 

Nevada is a UIC Primacy State for Class V wells. In this state, construction and

operation of aquifer recharge and ASR wells are prohibited except as authorized by permit by

the State Engineer. The State Engineer must determine that the project is hydrologically feasible

and that it will not cause harm to users of land or other water within the area of hydrological

effect of the project. The permit specifies the capacity and plan of operation of the recharge

project, any required monitoring, and any other conditions believed necessary to protect ground

water.

Oklahoma is a UIC Primacy State for Class V wells. The state has incorporated by

reference into the Oklahoma Administrative Code those parts of 40 CFR Part 124 and Parts 144

to 148 that apply to the UIC program (252-652-1-3 OAC). Thus, aquifer recharge and ASR

wells in the state are authorized by rule in accordance with the existing federal requirements.

Oregon is a Primacy State for UIC Class V wells. In this state, the UIC program is

administered by the Department of Environmental Quality. However, the Oregon

Administrative Rules (OAR) contain special provisions administered by the Water Resources

Department addressing ASR and artificial ground water recharge (OAR 690 Division 350). 

OAR requires a limited license for ASR testing before a permanent ASR permit may be obtained

(690-350-0010(2) OAR). The injection source water for ASR is required to comply with

drinking water standards, treatment requirements, and performance standards established by the
September 30, 1999 44

state Health Department or maximum measurable levels established by the Environmental

Quality Commission, whichever are more stringent. No license or permit may establish

concentration limits for water to be injected for ASR in excess of standards established by the

Health Department or the Environmental Quality Commission (690-350-0010(6)(a)-(c) OAR). 

Use of artificially recharged waters requires a secondary ground water permit specifying the

maximum diversion rate and volume of withdrawals and allowable uses of stored recharged

water (690-350-0130 OAR).

South Carolina is a UIC Primacy State for Class V wells. In this state, aquifer recharge

and ASR wells are prohibited except as authorized by permit. Injection may not commence until

construction is complete, the permittee has submitted notice of completion to the Department of

Health and Environmental Control (DHEC), and DHEC has inspected the well and found it in

compliance. DHEC will establish maximum injection volumes and pressures and other such

permit conditions as necessary to assure that fractures are not initiated in the confining zone

adjacent to the USDW and to assure compliance with operating requirements. The movement of

injected fluids containing contaminants into USDWs is prohibited if the contaminant may cause

a violation of any drinking water standard or otherwise adversely affect health. 

Texas is a UIC Primacy State for Class V wells. In this state, underground injection is

prohibited, unless authorized by permit or rule. By rule, injection into an aquifer recharge well

is authorized , although the Texas Natural Resources Control Commission may require the

owner or operator of a well authorized by rule to apply for and obtain an injection well permit. 

No permit or authorization by rule is allowed where an injection well causes or allows the

movement of fluid that would result in the pollution of a USDW. 

Washington is a UIC Primacy State for Class V wells. In this state, an individual permit

is required to operate an aquifer recharge or ASR well. In addition, Washington has set

standards for direct ground water recharge projects using reclaimed water. These rules primarily

address the standards and treatment requirements for the reclaimed water, when injected into

potable and non-potable ground water.

Although an ASR well exist in Tennessee, the Tennessee Department of Environment

and Conservation (TDEC), Division of Water Supply, regulates this well as a Class V UIC

experimental well. The TDEC indicated that this injection well was permitted as an

experimental well because, although aquifer storage and retrieval system technology had been

demonstrated in other states, this is the first such system to be constructed in Tennessee (TDEC,

1996a; TDEC, 1996b). TDEC issued the permit to the MLGWD in 1996 (TDEC, 1996c). This

permit expires in 2001. The MLGWD is permitted to inject no more than 600 gallons per minute

of treated drinking water into the ASR system at a maximum injection pressure of 125 psi. The

MLGWD is also required to conduct injectate sampling and analysis for injectate quality at the

start up of each injectate event. 
September 30, 1999 45

ATTACHMENT A

ASR WELL DATA REPORTED IN LITERATURE

Location Operational Information Storage Zone Data Source Number of 

ASR Wells 

Brick, NJ Began operations in 1996. N/A 1 Horvath, 1997

Gordon’s Corner, NJ Began operations in 1972. Clayey sand 2 Pyne, 1995

Murray Avenue, NJ Began operations in 1994. Clayey sand 2 Pyne, 1995

Swimming River, NJ Began operations in 1993. Clayey sand 1 Pyne, 1995

Injection into aquifer with high iron

concentration due to siderite and pyrite.

Wildwood, NJ Began operations in 1968. Sand 4 Amans and McLeod,

Also beneficial for preventing saltwater (Cohansey aquifer) 1991; Horvath, 1997;

intrusion. Lacombe, 1997; 

Pyne, 1995

Chesapeake, VA Began operations in 1990. Sand 1 Horvath, 1997; 

Pyne, 1995

Boynton Beach, FL Began operations in 1993. Limestone 1 Pyne, 1995

Injection into brackish aquifer. (1 additional well

expected)

Cocoa, FL Began operations in 1987. Limestone 6 wells, plans for Pyne, 1995

Injection into brackish aquifer. 4 more wells

Collier County, FL Began operations in August 1998. Limestone 1 Walker, 1999

Injection into brackish aquifer. (Hawthorne Zone II

Aquifer) 

Hillsborough County, FL Operational testing is expected in 1998 Limestone 1 test well to be McNeal et al., 1997

and 1999. (lower Suwanee installed

Injection into a brackish aquifer. Limestone) (Construction to

be complete by

December, 1997)

Manatee, FL Began operations in 1983. Limestone 1 Pyne, 1995

Injection into brackish aquifer.

Marathon, FL Began operations in 1994. Sand 1 test well, plans Pyne, 1995

Injection into a saline aquifer. for 7 more wells

Marco Island, FL Injection into a brackish aquifer. Limestone 1 test well Horvath et al., 1997

Peace River, FL Began operations in 1985. Limestone 9 Horvath, 1997; 

Injection into brackish aquifer. Pyne, 1995; 

Singer et al., 1993;

Southwest Florida

Water Management

District, website

Port Malabar, FL Began operations in 1989. Limestone 1 Pyne, 1995

Injection into brackish aquifer.

Tampa, FL Permit had been granted, but N/A 1 Deuerling, 1997

construction had not yet begun in 1997.
ATTACHMENT A

ASR WELL DATA REPORTED IN LITERATURE (continued)

Location Operational Information Storage Zone Data Source Number of 

ASR Wells 

September 30, 1999 46

Kerrville, TX Began operations in 1991. Sandstone 2 Amans and McLeod,

(Hosston-Sligo 1988; Amans and

formation in the McLeod, 1991; Pyne,

Lower Trinity 1995; Singer et al.,

Aquifer) 1993

Ankeny, IA Part of a research and demonstration Sandstone 1 test well Miller and Beavers,

project. (Jordon aquifer) 1997

Injection into a poor quality aquifer

(slightly brackish).

Wichita, KS Research and demonstration project Equus beds N/A United States

jointly sponsored by the city of Wichita wellfield Geological Survey,

and the USGS to determine water- website

quality effects of ASR on ground water.

Highlands Ranch, CO Began operations in 1993. Sand 1 well, 2 more Pyne, 1995;

expected Singer et al., 1993

Calleguas, CA Began operations in 1992. Sand 1 well, 4 more Breault, 1997;

Electricity generation during recharge (North Las Posas expected by end Calleguas Municipal

periods. Ground Water of 1997, Water District, website;

Basin) investigating Pyne, 1995

sites for 25 more

wells

Goleta, CA Began operations in 1978. Silty, clayey sand 9 Pyne, 1995

All wells were retrofitted for ASR and

recharge purposes. 

Recharge occurred in only seven years

between 1978 and 1988.

Lancaster, CA One test well operated in 1994, one (Lancaster Aquifer) 2 Antelope Valley Board

other well currently in test phase. of Trade, website

Oxnard, CA Began operations in 1989. Alluvial aquifer 5 City of Oxnard, 1996;

overlain by thick, Pyne, 1995

areally extensive

clay deposits

(Oxnard Aquifer)

Pasadena, CA Began operations in 1992. Sand (Raymond 2 Pyne, 1995

Considering electricity generation Ground Water

during recharge. Basin)

Salem, OR Pilot ASR well program undertaken in Basalt 4 Eckley, 1999

1994/1995.

Seattle, WA Began operations in 1992. Glacial drift 3 Pyne, 1995

N/A Not available.
September 30, 1999 47

ATTACHMENT B

ASR FACILITIES AND WELLS IN FLORIDA

Updated: 12/07/98

Facility Name Map # Application ASR Pre- Construction Well Operational Operation

Type* Application Permit Issued Constructed Testing Permit

Construction

Received

Boynton Beach ASR TDW 14 X

Broward County 2A WTP RGW 15 X

Miami-Dade Southwest Wellfield RGW 17 X

Miami-Dade West Wellfield RGW 18 X

Deerfield Beach ASR TDW 16 X

Fiveash WTP TDW

future RGW 24 X

Miami Beach ASR TDW 21 X

Taylor Creek ASR RSW 12 X (not used)

West Palm Beach ASR TDW

interim PTS 13 X

future RSW

Peace River

 Wells 1-9 TDW 5 X X

 Wells 10-21

Palm Beach County System #3 TDW

future RGW 22 X

Delray Beach X (WMD TDW 26 X

permit) 

Collier County TDW 8 X

FKAA Marathon TDW 19 X(not used)

Corkscrew (Lee County) 

 Well #1 TDW 6 X X

 Wells 2-6

Marco Lakes 

 Well #1 PTS 7 X X

 Wells 2-9

Punta Gorda TDW 23 X

San Carlos Estates (Bonita Springs Utilities) TDW 29 X

Kehl Canal (Bonita Springs Utilities) PTS 30 X

Fort Myers TDW 31 X

North Reservoir (N. Ft. Myers) TDW 33 X
ATTACHMENT B

ASR FACILITIES AND WELLS IN FLORIDA (continued)

Facility Name Map # Application ASR Pre- Construction Well Operational Operation

Type* Application Permit Issued Constructed Testing Permit

Construction

Received

September 30, 1999 48

Olga RSW 34 X

Tampa - Rome Avenue 

 Well #1 TDW 1 X X

 Wells 2-9

Tampa - Hillsborough River PTS 2 X

Lake Manatee

 Wells B-1 and B-2 TDW 4 X X

 Wells B-3 through B-6

Cocoa - Claude H. Dyal 

 Wells 1-6 TDW 9 X X

 Wells 6-10

Palm Bay TDW 11 X

Sunrise Springtree TDW 20 X

*ASR Types:

TDW Potable through drinking water plant.

RSW Raw surface water.

RGW Raw ground water.

PTS Partially treated surface water.
September 30, 1999 49

ATTACHMENT C

STATE AND LOCAL PROGRAM DESCRIPTIONS

This attachment does not describe every state’s regulatory requirements; instead, it

focuses on the ten states where aquifer recharge and ASR wells are known to exist: California,

Colorado, Florida, Idaho, Nevada, Oklahoma, Oregon, South Carolina, Texas, and Washington. 

Altogether, these ten states have a total of 1,051 documented aquifer recharge and ASR wells,

which is approximately 87 percent of the documented well inventory for the nation. 

California

USEPA Region 9 directly implements the UIC program for Class V injection wells in

California. The California Water Quality Control Act (WQCA), however, establishes broad

requirements for the coordination and control of water quality in the state, sets up a State Water

Quality Control Board, and divides the state into nine regions, with Regional Water Quality

Control Boards (RWQCBs) that are delegated responsibilities and authorities to coordinate and

advance water quality in each region (Chapter 4 Article 2 WQCA). A RWQCB can prescribe

requirements for discharges (waste discharge requirements, or WDRs) into the waters of the state

(13263 WQCA). These WDRs can apply to injection wells (13263.5 and 13264(b)(3) WQCA). 

In addition, the WQCA specifies that no provision of the Act or ruling of the State Board or a

Regional Board is a limitation on the power of a city or county to adopt and enforce additional

regulations imposing further conditions, restrictions, or limitations with respect to the disposal of

waste or any other activity which might degrade the quality of the waters of the state (13002

WQCA).

Permitting

The WQCA provides that any person operating, or proposing to operate, an injection well

(as defined in §13051 WQCA) must file a report of the discharge, containing the information

required by the Regional Board, with the appropriate Regional Board (13260(a)(3) WQCA). 

Furthermore, the RWQCB, after any necessary hearing, may prescribe requirements concerning

the nature of any proposed discharge, existing discharge, or material change in an existing

discharge to implement any relevant regional water quality control plans. The requirements also

must take into account the beneficial uses to be protected, the water quality objectives

reasonably required for that purpose, other waste discharges, and the factors that the WQCA

requires the Regional Boards to take into account in developing water quality objectives, which

are specified in §13241 of the WQCA (13263(a) WQCA). However, a RWQCB may waive the

requirements in 13260(a) and 13253(a) as to a specific discharge or a specific type of discharge

where the waiver is not against the public interest (13269(a) WQCA).

If treated wastewater is planned to be used for aquifer recharge, the approach followed by

RWQCBs is to issue site-specific WDRs. In addition, the Department of Health Services must

review and approve the application. The recharge injectate must meet drinking water MCLs at

the point of injection. County water districts and/or county health departments may supplement

the requirements. If potable water is planned to be used for aquifer recharge, the projects are

reviewed and regulated by health departments.
September 30, 1999 50

Siting and Construction Requirements

Department of Water Resources Bulletin 74-90 provides specifications for well

construction standards. 

Operating Requirements

Not specified by statute or regulations.

Monitoring Requirements

Not specified by statute or regulations.

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

Not specified by statute or regulations.

Colorado

USEPA Region 8 directly implements the UIC program for Class V injection wells in

Colorado. The State of Colorado does not have rules explicitly addressing aquifer storage and

recovery, but it has enacted requirements directly addressing artificial recharge. However, those

rules apply primarily to the permitting of extraction and use of waters artificially recharged

(Rules and Regulations for the Permitting and Use of Waters Artificially Recharged into the

Dawson, Arapahoe, and Laramie-Fox Hills Aquifers, 2 Colorado Code of Regulations (CCR)

402-11). The rules do provide that water artificially recharged into a Denver Basin aquifer,

whether for the maintenance of water levels or for subsequent extraction, shall be, at the time of

extraction, fully consumable and/or reusable (Rule 5.1).

Permitting

Permitting requirements under the artificial recharge rules apply only to extraction. 

However, an application to construct a well to extract artificially recharged water must include

information about whether the aquifer is confined or unconfined at the injection site(s) and other

information concerning the aquifer at and around the well or wells through which the water was

injected, including an accounting of the timing, amount, and location(s) of injection of

artificially recharged water which is to be extracted through the proposed well (Rule 6.3.1).
September 30, 1999 51

Like almost all western states, Colorado issues permits for the extraction and use of both

surface water and ground water. Permits for extraction and use must consider impacts to

existing wells and other water rights. The rules on permitting and use of waters artificially

recharged into the Dawson, Denver, Arapahoe, and Laramie-Fox Hills aquifers define extraction

well as an existing permitted well or a well that has been, or will be constructed, for the purpose

of extracting artificially recharged water. When applied to an existing permitted well, this term

may describe a well which has been authorized for the extraction of an amount of water beyond

the amount of naturally occurring ground water authorized for withdrawal under the existing

permit (Rule 4.3.8). Use of totalizing flow meters is required for measuring the amount of all

water injected and extracted (Rule 5.7.1). The State Engineer accounts for water that is

artificially recharged and administers the orderly withdrawal of such water to prevent injury to

existing water users and water rights holders.

Siting and Construction Requirements

Colorado’s water well construction rules (2. CCR 402-2) do not state explicitly that they

apply to artificial recharge wells, but because they apply to the construction of water wells, the

state applies them. A permit issued by the State Engineer is required prior to constructing a new

or replacement well (Water Well Construction Rule 6).

Siting and construction requirements under the artificial recharge rules apply only to

extraction. The water well construction rules contain detailed requirements concerning well

location and minimum well construction standards (Rule 10). They include specifications for

well casing, sealing and grouting, and disinfection (Rule 10.4 - 10.9 and Rule 17).

Operating Requirements

The wells used for artificial recharge and/or extraction are required to have totalizing

flow meters installed to measure the amount of all water injected and extracted (Rule 5.7). If the

meter is not operational, the well may not be operated. 

Monitoring Requirements

Not specified by statute or regulations.

Mechanical Integrity Testing

Not specified by statute or regulations.
September 30, 1999 52

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

Not specified by statute or regulations.

Florida

Florida is a UIC Primacy State for Class V wells. Chapter 62-528 of the Florida

Administrative Code (FAC), effective June 24, 1997, establishes the state's UIC program, and

Part V of Chapter 62-528 (62-528.600 to 62-528.900) addresses criteria and standards for Class

V wells. Class V wells are grouped for purposes of permitting into eight categories. Aquifer

recharge wells fall into Group 2. Wells associated with an aquifer storage and recovery system

fall into Group 7.

Permitting

Underground injection through a Class V well is prohibited except as authorized by

permit by the Department of Environmental Protection. Owners and operators are required to

obtain a Construction/Clearance Permit before receiving permission to construct. The applicant

is required to submit detailed information, including well location and depth, description of the

injection system and of the proposed injectate, and any proposed pretreatment. When sitespecific conditions indicate a threat to a USDW, additional information must be submitted. The

state generally issues letters of authorization, even when potable water is injected and no permit

is required. The letter of authorization can include specific conditions with respect to the

standards that must be met by the injected water, monitoring requirements for flow rate and

pressure, sampling of monitoring well, and reporting. Finally, all Class V wells are required to

obtain a plugging and abandonment permit.

In addition, local Water Management Districts and/or County Environmental

Management Departments also review applications for aquifer storage and recovery wells. 

Siting and Construction Requirements

Specific construction standards for Class V wells have not been enacted by Florida,

because of the variety of Class V wells and their uses. Instead, the state requires the well to be

designed and constructed for its intended use, in accordance with good engineering practices,

and approves the design and construction through a permit. The state can apply any of the

criteria for Class I wells to the permitting of Class V wells, if it determines that without such

criteria the Class V well may cause or allow fluids to migrate into a USDW and cause a violation

of the state’s primary or secondary drinking water standards, which are contained in Chapter 62-

550 of the FAC. However, if the injectate meets the primary and secondary drinking water

quality standards and the minimum criteria contained in Rule 62-520-400 of the FAC, Class I

injection well permitting standards will not be required.
September 30, 1999 53

Class V wells are required to be constructed so that their intended use does not violate

the water quality standards in Chapter 62-520 FAC at the point of discharge, provided that the

drinking water standards of 40 CFR Part 142 (1994) are met at the point of discharge. 

Operating Requirements

All Class V wells are required to be used or operated in such a manner that does not

present a hazard to a USDW. Pretreatment of injectate must be performed, if necessary to ensure

the fluid does not violate the applicable water quality standards in 62-520 FAC. 

Monitoring Requirements

Monitoring generally will be required for Group 2 and 7 wells, unless the wells inject

fluids that meet the primary and secondary drinking water standards in 62-550 FAC and the

minimum criteria in Rule 62-520, and the injection fluids have been processed through a

permitted drinking water treatment facility (62-528.615 (1)(a)2 FAC). Monitoring frequency

will be based on well location and the nature of the injectate and will be addressed in the permit. 

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

The owner or operator of any Class V well must apply for a plugging and abandonment

permit when the well is no longer used or usable for its intended purpose. Plugging must be

performed by a licensed water well contractor.

Idaho

Idaho is a UIC Primacy State for Class V wells and has promulgated regulations for the

UIC Program in the Idaho Administrative Code (IDAPA), Title 3, Chapter 3. Deep injection

wells are defined as more than 18 feet in vertical depth below the land surface (37.03.03.010.11

IDAPA). Wells are further classified, with Class V Subclass 5R21 defined as aquifer recharge

wells (37.03.03.025.01.m IDAPA).
September 30, 1999 54

Permitting

Construction and use of shallow injection wells is authorized by rule, provided that

inventory information is provided and use of the well does not result in unreasonable

contamination of a drinking water source or cause a violation of the state’s water quality

standards that would affect a beneficial use (37.03.03.025.03.d. IDAPA). Construction and use

of Class V deep injection wells is authorized by permit (37.03.03.025.03.c IDAPA). The

regulations outline detailed specifications for the information that must be supplied in a permit

application (37.03.03.035 IDAPA).

Operating Requirements

Standards for the quality of injected fluids and criteria for location and use are

established for rule-authorized wells, as well as for wells requiring permits. The rules are based

on the premise that if the injected fluids meet MCLs for drinking water for physical, chemical,

and radiological contaminants at the wellhead, and if ground water produced from adjacent

points of diversion for beneficial use meets the water quality standards found in Idaho’s “Water

Quality Standards and Wastewater Treatment Requirements,” 16.01.02 IDAPA, administered by

the Idaho Department of Health and Welfare, the aquifer will be protected from unreasonable

contamination. State officials may, when it is deemed necessary, require specific injection wells

to be constructed and operated in compliance with additional requirements (37.03.03.050.01

IDAPA (Rule 50)). Rule-authorized wells “shall conform to the drinking water standards at the

point of injection and not cause any water quality standards to be violated at the point of

beneficial use” (37.03.03.050.04.d IDAPA).

Monitoring Requirements

Monitoring, record keeping, and reporting may be required if state officials find that the

well may adversely affect a drinking water source or is injecting a contaminant that could have

an unacceptable effect upon the quality of the ground waters of the state (37.03.03.055 IDAPA

(Rule 55)).

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

There are no financial responsibility requirements for rule-authorized wells. Permitted

wells are required by the permit rule to demonstrate financial responsibility through a

performance bond or other appropriate means to abandon the injection well according to the

conditions of the permit (37.03.03.35.03.e IDAPA).
September 30, 1999 55

Plugging and Abandonment

The Idaho Department of Water Resources (IDWR) has prepared “General Guidelines for

Abandonment of Injection Wells,” which are not included in the regulatory requirements. IDWR

expects to approve the final abandonment procedure for each well. The General Guidelines

recommend the following:

C Pull the casing, if possible. If the casing is not pulled, cut the casing a minimum of two

feet below the land surface.

C The total depth of the well should be measured.

C If the casing is left in place, it should be perforated and neat cement with up to 5 percent

bentonite can be pressure-grouted to fill the hole. As an alternative, when the casing is

not pulled, course bentonite chips or pellets may be used. If the well extends into the

aquifer, the chips or pellets must be run over a screen to prevent any dust from entering

the hole. No dust is allowed to enter the bore hole because of the potential for bridging. 

Perforation of the casing is not required under this alternative.

C If the well extends into the aquifer, a clean pit-run gravel or road mix may be used to fill

the bore up to ten feet below the top of the saturated zone or ten feet below the bottom of

casing, whichever is deeper, and cement grout or bentonite clay used to the surface. The

use of gravel may not be allowed if the lithology is undetermined or unsuitable. 

C A cement cap should be placed at the top of the casing if it is not pulled, with a minimum

of two feet of soil overlying the filled hole/cap.

C Abandonment of the well must be witnessed by an IDWR representative.

Nevada

Nevada is a UIC Primacy State for Class V wells in which the Division of Environmental

Protection (DEP) administers the UIC Program. In addition, the State Engineer is authorized to

regulate the use of underground water, and projects for recharge and storage and recovery fall

under that jurisdiction. 

Nevada Revised Statutes (NRS) §§ 445A.300 - 445A.730 and regulations under the

Nevada Administrative Code (NAC) §§ 445A.810 - 445A.925 establish the state’s basic UIC

Program. The injection of fluids through a well into any waters of the state, including

underground waters, is prohibited without a permit issued by DEP (445A.465 NRS), although

the statute allows both general and individual permits (445A.475 NRS and 445A.480 NRS). 

Furthermore, injection of a fluid that degrades the physical, chemical, or biological quality of the

aquifer into which it is injected is prohibited, unless the DEP exempts the aquifer and the federal

USEPA does not disapprove the exemption within 45 days after notice of it (445A.850 NRS). 

Regulations, particularly Chapter 445A NAC, “Underground Injection Control,” define and

elaborate these statutory requirements.
September 30, 1999 56

In addition, Chapter 534 of the Nevada Revised Statutes, “Underground Water and

Wells” addresses recharge and storage and recovery activities. 

Permitting

The UIC regulations specify detailed information that must be provided in support of

permit applications, including proposed well location, description of geology, construction plans,

proposed operating data on rates and pressures of injection, analysis of injectate, analysis of fluid

in the receiving formation, proposed injection procedures, and corrective action plan (445A.867

NAC). The DEP may, however, modify the permit application information required for a Class

V well. 

The underground water statute provides that the State Engineer will supervise all wells

tapping artesian water or water in definable underground aquifers, except wells for domestic

purposes that do not require a permit (534.030.4 NRS). The State Engineer may establish a

ground water basin water board to advise on approval of applications to issue permits to drill

wells or take related actions (534.035 NRS). Persons seeking to sink or bore a well in any basin

or portion thereof in the state designated by the State Engineer must first obtain a permit from

the State Engineer (534.050 NRS). The statute also provides that any person seeking to operate

a project for recharge, storage, and recovery of water must obtain a permit from the State

Engineer. The State Engineer must determine that the project is hydrologically feasible and that

it will not cause harm to users of land or other water within the area of hydrological effect of the

project (534.250 NRS). A permit application must supply detailed information about the

project, including the following:

C Evidence of financial and technical capacity;

C The source, quality and annual quantity of water proposed to be recharged, and the

quality of the receiving water; and

C A study that demonstrates the area of hydrological effect of the project, that the project is

hydrologically feasible, that the project will not cause harm to users of land and water

within the area of hydrological effect; the percent of recoverable water.

The permit will specify the capacity and plan of operation of the project, any required

monitoring, and any conditions (534.270 NRS). 

Siting and Construction Requirements

The State of Nevada specifies that all injection wells must be situated on a well-drained

site not subject to inundation by a 100-year flood and sited in such a way that the well injects

into a formation that is separated from any USDW by a confining zone that is free of known

open faults or fractures within the area of review. It must be cased from the finished surface to

the top of the zone for injection and cemented to prevent movement of fluids into or between

USDWs. All injections must be through tubing set on a mechanical packer and the packer must
September 30, 1999 57

be set between the top of the zone for injection and the bottom of the next highest USDW and as

close as possible to the top of the injected interval (445A.908 NAC).

Operating Requirements

Injection of a fluid that degrades the physical, chemical, or biological quality of the

aquifer into which it is injected is prohibited, unless the DEP exempts the aquifer and the

USEPA does not disapprove the exemption within 45 days after notice of it (445A.850 NRS). 

Monitoring Requirements

Monitoring frequency for injection pressure, pressure of the annular space, rate of flow,

and volume of injected fluid is specified by the permit for Class V wells. Analysis of injected

fluid must be conducted with sufficient frequency to yield representative data. Mechanical

integrity testing is required once each 5 years, by a specified method (445A.916 NAC).

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

A bond is required in favor of the state for the costs of plugging and abandonment of the

well, except that the bond may be waived for Class V wells upon adequate proof of financial

responsibility (445A.871 NAC).

Plugging and Abandonment

A plugging and abandonment plan and cost estimate must be prepared for each well, and

reviewed annually. Before abandonment, a well must be plugged with cement in a manner that

will not allow the movement of fluids into or between USDWs (445A.923 NAC).

Oklahoma

Oklahoma is a UIC Primacy State for Class V wells. The state has incorporated by

reference into the Oklahoma Administrative Code (OAC) those parts of 40 CFR Part 124, and

Parts 144 to 148 that apply to the UIC program (252-652-1-3 OAC).

Permitting

Applicants for Class V injection well facilities are required to perform ground water

monitoring, provide an analysis of injected fluids and a description of the geologic strata through

which and into which injection is taking place, and provide any addition information that the

applicant believes is necessary to comply with 40 CFR 144.12 (252:652-5-3 OAC).
September 30, 1999 58

Siting and Construction Requirements

Not specified by statute or regulations.

Operating Requirements

Not specified by statute or regulations.

Monitoring Requirements

Not specified by statute or regulations.

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

Not specified by statute or regulations.

Oregon

Oregon is a Primacy State for UIC Class V wells. The UIC program is administered by

the Department of Environmental Quality (DEQ). Under the State’s Administrative Rules

(OAR) pertaining to underground injection, “underground injection activity” means any activity

involving underground injection of fluids, including waste disposal wells and ground water

recharge wells. A “waste disposal well” is defined as any bored, drilled, driven or dug hole,

whose depth is greater than its largest surface dimension, which is used or is intended to be used

for disposal of sewage, industrial, agricultural, or other wastes and includes drain holes,

drywells, cesspools and seepage pits, along with other underground injection wells (340-044-

0005(22) OAR). Construction and operation of a waste disposal well is prohibited without a

water pollution control facility (WPCF) permit. Certain categories of wells are prohibited

entirely. Wells used for underground injection activities that allow the movement of fluids into a

USDW if such fluids may cause a violation of any primary drinking water regulation or

otherwise create a public health hazard or have the potential to cause significant degradation of

public waters are prohibited (340-044-0015(4)(d) OAR). The rules also provide that any

underground injection activity which may cause, or tend to cause, pollution of ground water may

be approved by DEQ in addition to other permits or approvals required by other federal, state, or

local agencies. 

OAR contain special provisions administered by the Water Resources Department

addressing ASR and artificial ground water recharge (OAR 690 Division 350). ASR is defined
September 30, 1999 59

as the storage of water from a separate source that meets drinking water standards in a suitable

aquifer for later recovery and not having as one of its primary purposes the restoration of the

aquifer (690-350-0010(1)(a) OAR). Artificial ground water recharge is defined as the

intentional addition of water diverted from another source to a ground water reservoir (690-350-

0110(1) OAR). 

Permitting

ASR requires a limited license for ASR testing before a permanent ASR permit may be

obtained (690-350-0010(2) OAR). The limited license may cover ASR testing for a single well

or same-aquifer wells in a wellfield. The injection source water for ASR is required to comply

with drinking water standards, treatment requirements, and performance standards established by

the state Health Department or maximum measurable levels established by the Environmental

Quality Commission, whichever are more stringent. Conditions are placed in the limited license

or permit to minimize, to the extent technically feasible, practical, and cost-effective, the

concentration of constituents in the injection source water that are not naturally present in the

aquifer. No license or permit may establish concentration limits for water to be injected for ASR

in excess of standards established by the Health Department or the Environmental Quality

Commission (690-350-0010(6)(a)-(c) OAR). If the injection source water contains regulated

constituents that are detected at greater than 50 percent of the established levels, the ASR limited

license or permit may require the permittee to employ technically feasible, practical, and costeffective methods to minimize concentrations of such constituents in the injection source water. 

Constituents that are associated with disinfection of the water may be injected into the aquifer up

to the standards established in the state. Further restrictions may be placed on certain

constituents if the Water Resources Department finds that they will interfere with or pose a

threat to the maintenance of the water resources of the state for present or future beneficial uses. 

An application for a limited license must specify the proposed source for injection water,

maximum diversion rate, maximum injection rate at each well, maximum storage volume,

maximum storage duration, and maximum withdrawal rate at each well. It must specify the

proposed beneficial use or the intended disposal method for the recovered water. Access to

water for injection must be evidenced by a completed water availability statement from the local

watermaster, results from the DEQ's water availability model, or citation of an existing water

right. If the applicant is not the holder of the water right for the proposed ASR testing,

permission for use must be obtained. Applicants are encouraged to protect their ground water

supply through the development of a Wellhead Protection plan (690-350-0020 OAR).

The proposed ASR testing program must include water quality sampling, quality

assurance/quality control, and water level monitoring. The proposed system design must include

well construction information for any injection wells. Detailed preliminary hydrogeologic

information must be provided. Detailed information must be provided on the quality of the

source water and the quality of the receiving aquifer water. Application for a permanent ASR

permit requires submission of detailed information on all of the topics included in the application

for a limited license (690-350-0030 OAR). The Water Resources Department consults with the

Health Department and DEQ about the completeness of the applications for a limited license or

permit. 
September 30, 1999 60

An application for a ground water recharge permit must include all of the information

required under OAR 690-310-0040. Use of artificially recharged waters requires a secondary

ground water permit specifying the maximum diversion rate and volume of withdrawals and

allowable uses of stored recharged water (690-350-0130 OAR).

Siting and Construction Requirements

The permit application must include the proposed system design, including well

construction information, the wellhead assembly, piping system for injection and recovery, and

other conceptual design components of the system. A licensed professional must develop this

information (690-350-0030(4)(b)(B) OAR). 

Operating Requirements

Not specified by statute or regulations.

Monitoring Requirements

Not specified by statute or regulations.

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

The state UIC requirements provide that upon discontinuance of use or abandonment a

waste disposal well is required to be rendered completely inoperable by plugging and sealing the

hole. All portions of the well which are surrounded by “solid wall” formation must be plugged

and filled with cement grout or concrete. The top portion of the well must be effectively sealed

with cement grout or concrete to a depth of at least 18 feet below the surface of the ground, or if

this method of sealing is not effective by a manner approved by the DEQ. The Water Resources

Department’s requirements for ASR and aquifer recharge wells do not address plugging or

abandonment. 
September 30, 1999 61

South Carolina

South Carolina is a UIC Primacy State for Class V wells and the UIC program is

implemented by the Department of Health and Environmental Control (DHEC). The UIC

regulations, found in Chapter 61 of the State Code of Regulations, divide Class V wells into two

groups, with aquifer recharge wells found in group A.

Permitting 

Class V.A. wells, which include recharge wells used to replenish the water in an aquifer,

are prohibited except as authorized by permit (R61-87.10.E.(1)(b) and (2)). The permit

application must include a description of the activities to be conducted, the name, address, and

location of the facility, the names and other information pertaining to the owner and operator, a

description of the business, and proposed operating data, including average and maximum daily

rate and volume of fluid to be injected, average and maximum injection pressure, and source and

an analysis of the chemical, physical, biological, and radiological characteristics of the injected

fluid; and drawings of the surface and subsurface construction of the well (R61-87.13.G(2)). 

The movement of fluids containing wastes or contaminants into USDWs as a result of injection

is prohibited if the waste or contaminant may cause a violation of any drinking water standard or

otherwise adversely affect the health of persons (R61-87.5).

Siting and Construction Requirements

Siting and operating criteria and standards for Class V.A wells require logs and tests,

which will be specified by DHEC in the permit, to identify and describe USDWs and the

injection formation (R61-87.14). 

Injection may not commence until construction is complete, the permittee has submitted

notice of completion to DHEC, and DHEC has inspected the well and found it in compliance 

(R61-87.13U).

Operating Requirements

Operating requirements for Class V.A wells are the same as those for Class II and III

wells (R61-87.14). DHEC will establish maximum injection volumes and pressures and such

other permit conditions as necessary to assure that fractures are not initiated in the confining

zone adjacent to a USDW and to assure compliance with operating requirements (R61-87.13V).

Monitoring Requirements

Monitoring requirements will be specified in the permit. Monitoring requirements for

Class V.A wells are the same as those for Class III wells, and may include monitoring wells

(R61-87.14.G). Quarterly reporting of monitoring results is required to DHEC (R61-87.14.I(1)). 
September 30, 1999 62

Mechanical Integrity Testing

Prior to granting approval for operation, DHEC will require a satisfactory demonstration

of mechanical integrity. Tests will be performed at least every 5 years (R61-87.14.G). 

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

A plugging and abandonment plan must be prepared and approved by DHEC (R61-

87.15).

Texas

Texas is a UIC Primacy State for Class V wells. The Injection Well Act (Chapter 27 of

the Texas Water Code) and Title 3 of the Natural Resources Code provide statutory authority for

the UIC program. Regulations establishing the UIC program are found in Title 30, Chapter 331

of the Texas Administrative Code (TAC). Aquifer recharge wells used to replenish water in an

aquifer are specifically defined as Class V wells (331.11 (a)(4)(F) TAC). Aquifer storage wells

used for the injection of water for storage and subsequent retrieval for beneficial use are also

specifically defined as Class V wells (331.11 (a)(4)(K) TAC). 

Permitting

Underground injection is prohibited, unless authorized by permit or rule (331.7 TAC). 

By rule, injection into a Class V well is authorized, although the Texas Natural Resources

Control Commission (TNRCC) may require the owner or operator of a well authorized by rule to

apply for and obtain an injection well permit (331.9 TAC). No permit or authorization by rule is

allowed where an injection well causes or allows the movement of fluid that would result in the

pollution of a USDW. A permit or authorization by rule must include terms and conditions

reasonably necessary to protect fresh water from pollution (331.5 TAC).

Siting and Construction Requirements

All Class V wells are required to be completed in accordance with explicit specifications

in the rules, unless otherwise authorized by the TNRCC. These specifications are:

C A form provided either by the Water Well Drillers Board or the TNRCC must be

completed.

C The annular space between the borehole and the casing must be filled from ground level

to a depth of not less than 10 feet below the land surface or well head with cement slurry. 

Special requirements are imposed in areas of shallow unconfined ground water aquifers

and in areas of confined ground water aquifers with artesian head.
September 30, 1999 63

C In all wells where plastic casing is used, a concrete slab or sealing block must be placed

above the cement slurry around the well at the ground surface; and the rules include

additional specifications concerning the slab.

C In wells where steel casing is used, a slab or block will be required above the cement

slurry, except when a pitless adaptor is used, and the rules contain additional

requirements concerning the adaptor.

C All wells must be completed so that aquifers or zones containing waters that differ

significantly in chemical quality are not allowed to commingle through the boreholecasing annulus or the gravel pack and cause degradation of any aquifer zone.

C The well casing must be capped or completed in a manner that will prevent pollutants

from entering the well.

C When undesirable water is encountered in a Class V well, the undesirable water must be

sealed off and confined to the zone(s) of origin (331.132 TAC).

Operating Requirements

None specified. Chapter 331, Subpart H, “Standards for Class V Wells” addresses only

construction and closure standards (331.131 to 331.133 TAC).

Monitoring Requirements

Not specified by statute or regulations.

Mechanical Integrity Testing

Injection may be prohibited for Class V wells that lack mechanical integrity. The

TNRCC may require a demonstration of mechanical integrity at any time if there is reason to

believe mechanical integrity is lacking. The TNRCC may allow plugging of the well or require

the permittee to perform additional construction, operation, monitoring, reporting, and corrective

actions which are necessary to prevent the movement of fluid into or between USDWs caused by

the lack of mechanical integrity. Injection may resume on written notification from the TNRCC

that mechanical integrity has been demonstrated (331.4 TAC).

Financial Assurance

Chapter 27 of the Texas Water Code, “Injection Wells,” enacts financial responsibility

requirements for persons to whom an injection well permit is issued. A performance bond or

other form of financial security may be required to ensure that an abandoned well is properly

plugged (§ 27.073). Detailed financial responsibility requirements also are contained in Chapter

331, Subchapter I of the state’s UIC regulations (331.141 to 331.144 TAC). A permittee is

required to secure and maintain a performance bond or other equivalent form of financial
September 30, 1999 64

assurance or guarantee to ensure the closing, plugging, abandonment, and post-closure care of

the injection operation. However, the requirement, unless incorporated into a permit, applies

specifically only to Class I and Class III wells (331.142 TAC).

Plugging and Abandonment

Plugging and abandonment of a well authorized by rule is required to be accomplished in

accordance with §331.46 TAC (331.9 TAC). In addition, closure standards specific to Class V

wells provide that closure is to be accomplished by removing all of the removable casing and

filling the entire well with cement to land surface. Alternatively, if the use of the well is to be

permanently discontinued, and if the well does not contain “undesirable” water, the well may be

filled with fine sand, clay, or heavy mud followed by a cement plug extending from the land

surface to a depth of not less than 10 feet. If the use of a well that does contain undesirable

water

is to be permanently discontinued, either the zone(s) containing undesirable water or the fresh

water zone(s) must be isolated with cement plugs and the remainder of the wellbore filled with

sand, clay, or heavy mud to form a base for a cement plug extending from the land surface to a

depth of not less than 10 feet (331.133 TAC).

Washington

Washington is a UIC Primacy State for Class V wells. Chapter 173-218 of the

Washington Administrative Code (WAC) establishes the state's UIC program. Under this

program, the policy of the Department of Ecology is to maintain the highest possible standards to

prevent the injection of fluids that may endanger ground waters which are available for

beneficial uses or which may contain fewer than 10,000 mg/l total dissolved solids. Consistent

with that policy, all new Class V injection wells that inject industrial, municipal, or commercial

waste fluids into or above a USDW are prohibited (172-218-090(1) WAC). Existing wells must

obtain a permit to operate. 

In addition, the state has enacted standards for direct ground water recharge projects

using reclaimed water (Water Reclamation and Reuse Standards, Section 3). These rules

primarily address the standards and treatment requirements for the reclaimed water, when

injected into potable ground water and when injected into nonpotable ground water. For potable

ground water, the requirements also include construction standards for withdrawal facilities,

requiring them to comply with 173-136 and 173-150 WAC. The rules include reclaimed water

sampling and analysis and monitoring requirements, operational requirements for the

reclamation plant, disinfection requirements, mandatory retention time prior to withdrawal, and

ground water monitoring requirements (Articles 3 to 6). However, these rules do not address

requirements for injection and/or withdrawal wells, except for the requirement pertaining to

wells withdrawing water from potable aquifers.
September 30, 1999 65

Permitting 

A permit must specify conditions necessary to prevent and control injection of fluids into

the waters of the state, including all known, available, and reasonable methods of prevention,

control, and treatment; applicable requirements in 40 CFR Parts 124, 144, 146; and any

conditions necessary to preserve and protect USDWs. Any injection well that causes or allows

the movement of fluid into a USDW that may result in a violation of any primary drinking water

standard under 40 CFR Part 141 or that may otherwise adversely affect the beneficial use of a

USDW is prohibited (173-218-100 WAC).

Siting and Construction Requirements

The state has promulgated minimum standards for construction and maintenance of wells

(173-160-010 through -560 WAC). However, injection wells regulated under Chapter 173-218

are specifically exempted from these constructions standards (173-160-010(3)(e) WAC).

Operating Requirements

The water quality standards for ground waters establish an antidegradation policy. The

injectate must meet the state’s ground water standards at the point of compliance (173-200-030

WAC).

Monitoring Requirements

Not specified by statute or regulations.

Mechanical Integrity Testing

Not specified by statute or regulations.

Financial Assurance

Not specified by statute or regulations.

Plugging and Abandonment

All wells not in use must be securely capped so that no contamination can enter the well

(173-160-085 WAC).
September 30, 1999 66

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