United States Department of Agriculture 353-CPS-1

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September 2020

NRCS reviews and periodically updates conservation practice standards. To obtain the current 

version of this standard, contact your Natural Resources Conservation Service State office or 

visit the Field Office Technical Guide online by going to the NRCS website at 

https://www.nrcs.usda.gov/ and type FOTG in the search field. 

USDA is an equal opportunity provider, employer, and lender.

Natural Resources Conservation Service 

CONSERVATION PRACTICE STANDARD 

MONITORING WELL 

CODE 353 

(no)

DEFINITION 

A well designed and installed to obtain representative ground water samples and hydrogeologic

information. 

PURPOSE 

This practice is used to accomplish the following purpose: 

• To provide controlled access for sampling ground water near an agricultural waste storage facility,

waste treatment facility, or other area of concern to detect the occurrence of seepage and to

monitor ground water quality through time. 

CONDITIONS WHERE PRACTICE APPLIES 

This practice applies to the design, installation, and development of monitoring wells near components of

an agricultural waste management system. 

This practice does not apply to— 

• Methods for developing a ground water monitoring plan. 

• Methods for collection of ground water samples. 

• Analysis or interpretation of laboratory test results. 

• Monitoring of subsurface waters in the vadose (unsaturated) zone. 

• Installation of wells for any other purpose. 

• Temporary exploratory drill holes. 

CRITERIA 

General Criteria Applicable to All Purposes 

Permits 

The landowner is responsible for obtaining all necessary permits for the work prior to construction. The

contractor is responsible for locating all buried utilities in the project area, including drainage tile and other

structural measures. 

Hydrogeologic site characterization 

Use guidance provided in the ASTM International, (ASTM) D5092/D5092M, “Standard Practice for Design

and Installation of Groundwater Monitoring Wells,” to conduct surface and subsurface investigations within

the area of concern prior to the design of a monitoring well. Use this information to develop a conceptual

hydrogeologic model of the site, identify probable ground water flow paths, and determine the target

monitoring zones. 
Use National Engineering Handbook (NEH) (Title 210), Part 631, “Geology,” for methodologies for

identification, field-testing, and interpretation of geologic material and mass factors that affect movement

and flow direction of ground water within the area of concern. 

Planning 

Locate and describe any tile lines, subsurface drains, surface drains, irrigation ditches, irrigation wells,

water supply wells, septic drain fields, infiltration strips, quarries, mines, and other water

control/management features that influence the flow of local subsurface and surface water. 

Identify and describe other relevant features that influence subsurface water flow such as hard pans, sand

boils, animal burrows, seasonal desiccation, high shrink/swell soils, dense till, depth of frost line, or

permafrost. 

Estimate the vertical and lateral seasonal variability in the water table using guidance provided in 210-

NEH, Part 651, Chapter 7, “Geologic and Groundwater Considerations.” 

Write a report of the hydrogeologic investigation and include a geologic evaluation map or sketches of all

identified features and interpretations. 

Layout 

Use the hydrogeologic investigation report to determine the optimum locations of monitoring wells, both

up-gradient and down-gradient of the waste storage facility or in the area of concern. 

In highly fractured rock and in karst aquifers, locate the monitoring wells in the zones of highest

permeability, even if locations are offsite. 

Design 

The design of all components of the monitoring well must conform to criteria provided in ASTM

D5092/D5092M. 

Materials 

Materials used for the construction of monitoring wells must not chemically react with the ground water

and must not leach substances into the ground water. Avoid quick-setting cements containing additives

that may leach from the cement and influence the chemistry of water samples collected from the

monitoring well. 

For conventionally screened and filter-packed ground water monitoring wells located in sand and gravel

aquifers and other granular materials, ensure the grain size distribution contains less than 50 percent finer

than the 200 sieve and less than 20 percent clay-sized material. 

Ensure all materials used in construction, development, and sealing are free of contaminants prior to

installation. 

Use only commercial well screens or slotted pipe. 

Use only threaded jointed pipe or casing. Do not use glued or solvent-welded joints. 

Use only materials of adequate strength to withstand the forces of installation and well development. 

Installation 

Select the design protocol and installation method according to site-specific conditions identified during

the hydrogeologic investigation. 

Use only drilling or digging equipment capable of creating a stable, open, vertical hole for proper

installation of the monitoring well. 

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Installation methods must conform to ASTM D5092/D5092M, and ASTM D5787, “Standard Practice for

Monitoring Well Protection.” 

Direct push methods for installation are allowable provided they are consistent with guidance provided in

ASTM D6724/D6724M, “Standard Guide for Installation of Direct Push Groundwater Monitoring Wells,”

and ASTM D6725/D6725M, “Standard Practice for Direct Push Installation of Prepacked Screen

Monitoring Wells in Unconsolidated Aquifers.” 

Well protection 

Protect the monitoring well from damage from hazards such as frost action, surface drainage, animal or

equipment traffic, and lack of visibility. 

Establish positive surface drainage away from the wellhead. 

Establish a buffer zone with a minimum radius of 30 feet around the wellhead of the monitoring well. Use

fencing or other types of protection that excludes motorized vehicle access and livestock. 

Ensure that no storage, handling, mixing, or application of fertilizers, pesticides, or other agricultural

chemicals or cleaning of equipment used in the handling or application of such items occurs within the

buffer zone at any time. 

Development 

Well development procedures must target the most productive hydrogeologic zones penetrated by the

monitoring well. Seal the annular spaces adjacent to nonproductive zones to prevent cross contamination

and commingling of chemically or biologically different zones of underground or surface waters. Refer to

ASTM D5521/D5221M, “Standard Guide for Development of Groundwater Monitoring Wells in Granular

Aquifers,” for a description of the various development methods. Conduct the development process only

after completion of well installation, fill and sealing operations, and wellhead protection measures. 

Recordkeeping 

When writing records to describe a ground water site, refer to guidance provided in 210-NEH, Part 631,

Chapter 31, “Groundwater Investigation.” 

CONSIDERATIONS 

In developing the conceptual hydrogeologic model, consider effects of geomorphic processes, geologic

structures, regional stratigraphy, and soil and rock properties on subsurface flow patterns, location of

ground water recharge, and pollution potential. Consider the physical properties and methods of

movement in the environment of solutes and pollutants of interest and potential impact of relevant soil

properties (clay content, organic matter) when designing and locating the physical position and depth of a

monitoring well. Also, consider inherent physical and conductive properties of relevant soil horizons

(particle size, structure, and saturated hydraulic conductivity). 

Consider using geophysical tools in conjunction with penetrative exploratory techniques to improve and

refine the mapping of the location, shape, orientation, and extent of subsurface hydrogeologic units. 

Consider installing additional monitoring wells at other locations and at appropriate depths to ensure

identification of the location and direction of movement of any potential contaminant plume. 

Consider alternative drilling or digging methods for installing monitoring wells as provided in ASTM D6286,

“Standard Guide for Selection of Drilling Methods for Environmental Site Characterization.” 

Where frost heave is a concern, consider design alternatives that reduce the potential for frost heave

damage of the monitoring wells. 

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PLANS AND SPECIFICATIONS 

Prepare plans and specifications for constructing, installing, completing, and developing monitoring wells

that describe the requirements for applying the practice to achieve its intended purpose. 

OPERATION AND MAINTENANCE 

Operation and maintenance requirements must comply with the purpose of this standard. 

Maintenance and rehabilitation procedures must comply with criteria in ASTM D5978/D5978M, “Standard

Guide for Maintenance and Rehabilitation of Groundwater Monitoring Wells” to ensure acquisition of

ground water samples free of artificial turbidity, eliminate siltation of wells between sampling events, and

permit acquisition of accurate ground water levels and hydraulic conductivity test data from the zone

screened by the well. 

When no longer needed, close the well according to NRCS Conservation Practice Standard Well

Decommissioning (Code 351). 

REFERENCES 

ASTM D5092/D5092M. 2016. Standard Practice for Design and Installation of Groundwater Monitoring

Wells. ASTM International, West Conshohocken, PA, D5092-D5092M-16. http://www.astm.org

ASTM D5521/D5521M. 2018. Standard Guide for Development of Groundwater Monitoring Wells in

Granular Aquifers. ASTM International, West Conshohocken, PA, D5521/D5521M-18.

http://www.astm.org

ASTM D5787. 2014. Standard Practice for Monitoring Well Protection. ASTM International, West

Conshohocken, PA, D5787-14. http://www.astm.org

ASTM D5978/D5978M. 2016. Standard Guide for Maintenance and Rehabilitation of Groundwater

Monitoring Wells. ASTM International, West Conshohocken, PA, D5978/5978M-16. http://www.astm.org

ASTM D6286. 2012. Standard Guide for Selection of Drilling Methods for Environmental Site

Characterization. ASTM International, West Conshohocken, PA, D6285-12. http://www.astm.org

ASTM D6724/D6724M. 2016. Standard Guide for Installation of Direct Push Groundwater Monitoring

Wells. ASTM International, West Conshohocken, PA, 2018, D6724/D6724M-16. http://www.astm.org

ASTM D6725/D6725M. 2016. Standard Practice for Direct Push Installation of Prepacked Screen

Monitoring Wells in Unconsolidated Aquifers. ASTM International, West Conshohocken, PA,

D6725/D6725M-16. http://www.astm.org

USDA NRCS. 2012. National Engineering Handbook (NEH) (Title 210), Part 631, Geology. Washington,

D.C. https://directives.sc.egov.usda.gov/

USDA NRCS. 2010. NEH 651, Agricultural Waste Management Field Handbook, Chapter 7, Geology and

Groundwater Considerations. Washington, D.C. https://directives.sc.egov.usda.gov/

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