112 Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 

must be submitted for inclusion in the 

public docket. 

2. Tips for Preparing Your Comments. 

When submitting comments, remember 

to: 

• Identify the notice by docket 

number and other identifying 

information (subject heading, Federal 

Register date and page number). 

• Explain your views as clearly as 

possible, avoiding the use of profanity 

or personal threats. 

• Describe any assumptions and 

provide any technical information and/ 

or data that you used. 

• Provide specific examples to 

illustrate your concerns, and suggest 

alternatives. 

• Make sure to submit your 

comments by the comment period 

deadline identified. 

Dated: December 15, 2011. 

Susan E. Bromm, 

Director, Office of Federal Activities. 

[FR Doc. 2011–33462 Filed 12–30–11; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

[EPA–HQ–OW–2010–0884, FRL–9615–3] 

Effluent Limitations Guidelines and 

Standards for the Construction and 

Development Point Source Category 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Notice. 

SUMMARY: The Environmental Protection 

Agency is issuing a notice to solicit data 

and information associated with 

revisions to the Effluent Limitations 

Guidelines and New Source 

Performance Standards for the 

Construction and Development Point 

Source Category issued under the Clean 

Water Act. The regulation, as originally 

issued on December 1, 2009, established 

requirements that reduce pollutants 

discharged from construction and 

development sites, including 

requirements for a subset of sites to 

comply with a numeric effluent 

limitation for turbidity. On November 5, 

2010, EPA published a direct final rule 

and companion proposal staying the 

numeric turbidity limitation established 

by the December 2009 rule to correct a 

calculation error. The Agency received 

no adverse comments regarding the stay, 

and therefore, effective on January 4, 

2011, the numeric turbidity limitation 

was stayed. In today’s notice, EPA is 

seeking data on the effectiveness of 

technologies in controlling turbidity in 

discharges from construction sites and 

information on other related issues. 

Today’s notice also seeks comment on 

passive treatment data already available 

to the Agency. 

DATES: Comments must be received on 

or before March 5, 2012, 60 days after 

publication in the Federal Register. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–HQ– 

OW–2010–0884, by one of the following 

methods: 

• http://www.regulations.gov: Follow 

the on-line instructions for submitting 

comments. 

• Mail: Water Docket, U.S. 

Environmental Protection Agency, 

Mailcode: 28221T, 1200 Pennsylvania 

Ave. NW., Washington, DC 20460. 

• Hand Delivery: Water Docket, 

USEPA Docket Center, Public Reading 

Room, 1301 Constitution Avenue NW., 

Room 3334, EPA West Building, 

Washington DC 20004. Such deliveries 

are only accepted during the Docket’s 

normal hours of operation, and special 

arrangements should be made for 

deliveries of boxed information. 

Instructions: Direct your comments to 

Docket ID No. EPA–HQ–OW–2010– 

0884. EPA’s policy is that all comments 

received will be included in the public 

docket without change and may be 

made available online at http:// 

www.regulations.gov, including any 

personal information provided, unless 

the comment includes information 

claimed to be Confidential Business 

Information (CBI) or other information 

whose disclosure is restricted by statute. 

Do not submit information that you 

consider to be CBI or otherwise 

protected through www.regulations.gov 

or email. The http:// 

www.regulations.gov Web site is an 

‘‘anonymous access’’ system, which 

means EPA will not know your identity 

or contact information unless you 

provide it in the body of your comment. 

If you send an email comment directly 

to EPA without going through 

www.regulations.gov your email address 

will be automatically captured and 

included as part of the comment that is 

placed in the public docket and made 

available on the Internet. If you submit 

an electronic comment, EPA 

recommends that you include your 

name and other contact information in 

the body of your comment and with any 

disk or CD–ROM you submit. If EPA 

cannot read your comment due to 

technical difficulties and cannot contact 

you for clarification, EPA may not be 

able to consider your comment. 

Electronic files should avoid the use of 

special characters, any form of 

encryption, and be free of any defects or 

viruses. 

Docket: All documents in the docket 

are listed in the http:// 

www.regulations.gov index. Although 

listed in the index, some information is 

not publicly available, e.g., CBI or other 

information whose disclosure is 

restricted by statute. Certain other 

material, such as copyrighted material, 

will be publicly available only in hard 

copy. Publicly available docket 

materials are available either 

electronically in http:// 

www.regulations.gov or in hard copy at 

the Water Docket, EPA/DC, EPA West, 

Room 3334, 1301 Constitution Ave. 

NW., Washington, DC. The Public 

Reading Room is open from 8:30 a.m. to 

4:30 p.m., Monday through Friday, 

excluding legal holidays. The telephone 

number for the Public Reading Room is 

(202) 566–1744, and the telephone 

number for the Water Docket is (202) 

566–2426. 

FOR FURTHER INFORMATION CONTACT: Mr. 

Jesse W, Pritts, Engineering and 

Analysis Division, Office of Water 

(4303T), Environmental Protection 

Agency, 1200 Pennsylvania Ave. NW., 

Washington, DC 20460; telephone 

number: (202) 566–1038; fax number: 

(202) 566–1053; email address: 

pritts.jesse@epa.gov. 

SUPPLEMENTARY INFORMATION: 

A. Does this action apply to me? 

Entities potentially affected by this 

action include: 

Category Examples of affected entities 

North American 

Industry Classification System 

(NAICS) Code 

Industry ...................... Construction activities required to obtain NPDES permit coverage and performing the following activities: 

Construction of buildings, including building, developing and general contracting .............................. 236 

Heavy and civil engineering construction, including land subdivision .................................................. 237 


pmangrum on DSK3VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 113 

EPA does not intend the preceding 

table to be exhaustive, but provides it as 

a guide for readers regarding entities 

likely to be affected by this action. Other 

types of entities not listed on the table 

could also be affected. To determine 

whether your may be affected by this 

action, you should carefully examine 

the applicability criteria in Section 

450.10 of the December 1, 2009 final 

rule (74 FR 62995) and the definition of 

‘‘storm water discharges associated with 

industrial activity’’ and ‘‘storm water 

discharges associated with small 

construction activity’’ in existing EPA 

regulations at 40 CFR 122.26(b)(14)(x) 

and 122.26(B)(15), respectively. If you 

have questions regarding the 

applicability of this action to a 

particular activity, consult one of the 

persons listed in the preceding FOR

FURTHER INFORMATION CONTACT section. 

Table of Contents 

I. Overview 

II. Background 

A. NPDES Regulations, Construction 

General Permits and Applicability of 40 

CFR Part 450 Requirements 

B. Petitions for Administrative 

Reconsideration and Petitions for Review 

of the Final Construction and 

Development Regulation in the U.S. 

Circuit Court of Appeals for the Seventh 

Circuit 

C. EPA’s Unopposed Motion 

D. Stay of the Numeric Limitation 

III. Review of Treatment Data in EPA’s 

Current Dataset 

A. Approach to Calculating the December 

2009 Turbidity Limitation 

B. Passive and Semi-Passive Treatment 

Datasets 

C. Additional Data 

IV. Solicitation of Data and Comments on 

Numeric Effluent Limitations for 

Turbidity 

A. Control of Turbidity—Effectiveness, 

Cost and Feasibility of Different 

Technologies 

B. Sampling and Data Collection— 

Procedures and Protocols To Ensure 

Representativeness of Data; Differences 

in Analytical Equipment 

C. Effect of Storm Size, Intensity and 

Duration of Precipitation on Performance 

of Passive Treatment 

D. Exemptions—Design Storm Depth vs. 

Intensity 

E. Use of Treatment Chemicals, Disposal 

and Toxicity Concerns 

F. Cold Weather Considerations 

G. Small Sites That Are Part of a Larger 

Common Plan of Development or Sale 

H. Electric Utility Transmission Line 

Construction 

I. Overview 

EPA promulgated Effluent Limitations 

Guidelines and Standards for the 

Construction and Development Point 

Source Category (hereafter referred to as 

the ‘‘C&D rule’’) on December 1, 2009 

(74 FR 62995). The final rule established 

requirements based on Best Practicable 

Control Technology Currently 

Available, Best Available Technology 

Economically Achievable, Best 

Conventional Pollutant Control 

Technology, and New Source 

Performance Standards based on Best 

Available Demonstrated Control 

Technology. 

The rule included non-numeric 

requirements to: 

• Implement erosion and sediment 

controls; 

• Stabilize soils; 

• Manage dewatering activities; 

• Implement pollution prevention 

measures; 

• Prohibit certain discharges; and 

• Utilize surface outlets for 

discharges from basins and 

impoundments. 

The December 2009 final rule also 

established a numeric limitation on the 

allowable level of turbidity in 

discharges from certain construction 

sites. The technology basis for the final 

numeric limitation was passive 

treatment controls including polymeraided settling to reduce the turbidity in 

discharges. 

Since issuing the final rule, an error 

in EPA’s interpretation of the data used 

to establish the numeric limitation was 

identified in petitions from the U.S. 

Small Business Administration and the 

National Association of Home Builders 

(NAHB). Today’s notice seeks comment 

in the form of data and information on 

several of the issues raised in the 

petitions, as well as other topics. 

II. Background 

A. NPDES Regulations, Construction 

General Permits and Applicability of 40 

CFR Part 450 Requirements 

EPA promulgated the Phase I National 

Pollutant Discharge Elimination System 

(NPDES) stormwater regulations (55 FR 

47990) on November 16, 1990. The 

Phase I regulations require that 

dischargers must apply for and obtain 

authorization to discharge (or ‘‘permit 

coverage’’). One of the categories of 

dischargers that must obtain permits is 

discharges associated with construction 

activity, including clearing, grading, and 

excavation, if the construction activity: 

• Will result in the disturbance of five 

acres or greater; or 

• Will result in the disturbance of less 

than five acres of total land area that is 

a part of a larger common plan of 

development or sale if the larger 

common plan will ultimately disturb 

five acres or greater. 

See 40 CFR 122.26(b)(14)(x). 

The Phase II stormwater regulations, 

promulgated on December 8, 1999 (64 

FR 68722) extended permit coverage to 

construction activity that: 

• Will result in land disturbance of 

equal to or greater than one acre and 

less than five acres; or 

• Will result in disturbance of less 

than one acre of total land area that is 

part of a larger common plan of 

development or sale if the larger 

common plan will ultimately disturb 

equal to or greater than one and less 

than five acres. 

See 40 CFR 122.26(b)(15). 

Since 1992, EPA has issued a series of 

Construction General Permits (CGPs) 

that cover areas where EPA is the 

NPDES permitting authority. At present, 

EPA is the permitting authority in four 

states (Idaho, Massachusetts, New 

Hampshire, and New Mexico), the 

District of Columbia, Puerto Rico, all 

other U.S. territories with the exception 

of the Virgin Islands, Federal facilities 

in four states (Colorado, Delaware, 

Vermont, and Washington), most Indian 

lands and other specifically designated 

activities in specific states (e.g., oil and 

gas activities in Texas and Oklahoma). 

In areas where EPA is not the NPDES 

permitting authority, states issue general 

permits for construction activity. Many 

state permits contain requirements 

similar to those contained in the EPA 

CGP. In addition, a few state permits 

contain monitoring requirements and/or 

requirements to comply with numeric 

effluent limitations. For example, 

California’s, Washington’s, Oregon’s, 

Georgia’s and Vermont’s current CGPs 

include discharge monitoring 

requirements. In addition, California’s 

current CGP contains numeric effluent 

limitations for a subset of construction 

sites within the State. 

EPA issued new regulations at 40 CFR 

part 450 on December 1, 2009 (the C&D 

Rule). The C&D Rule applies to all 

construction stormwater discharges 

required to obtain NPDES permit 

coverage. The C&D rule applies to the 

entire country, not just the areas where 

EPA is the permitting authority. Any 

permit issued by a state or EPA after the 

effective date of the rule (which was 

February 1, 2010) must include the 

requirements contained in that rule. The 

requirements include BMPs but do not 

include a numeric limitation which was 

stayed on January 4, 2011. 

B. Petitions for Administrative 

Reconsideration and Petitions for 

Review of the Final Construction and 

Development Regulation in the U.S. 

Circuit Court of Appeals for the Seventh 

Circuit 

Following promulgation of the 

December 2009 final C&D rule, the 

Wisconsin Home Builders Association 


pmangrum on DSK3VPTVN1PROD with NOTICES
114 Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 

and the National Association of Home 

Builders (NAHB) filed petitions for 

review in the U.S. Circuit Courts of 

Appeals for the Fifth, Seventh, and DC 

Circuits. The petitions were 

consolidated in the Seventh Circuit. 

Subsequently, the Utility Water Act 

Group (UWAG) also filed suit in the 

Seventh Circuit. On July 8, 2010, the 

petitioners filed their briefs. 

In April 2010, the Small Business 

Administration (SBA) filed with EPA a 

petition for administrative 

reconsideration of several technical 

aspects of the C&D Rule. SBA identified 

potential deficiencies with the dataset 

that EPA used to support its decision to 

adopt the numeric turbidity limitation. 

In June 2010, the National Association 

of Homebuilders also filed a petition for 

administrative reconsideration with 

EPA incorporating by reference SBA’s 

argument regarding the deficiencies in 

the data. 

C. EPA’s Unopposed Motion 

On August 12, 2010, EPA filed an 

unopposed motion with the Court 

seeking to hold the litigation in 

abeyance until February 15, 2012 (see 

DCN 70084) and asking the Court to 

remand the record to EPA and vacate 

the numeric limitation portion of the 

rule. In addition, EPA agreed to 

reconsider the numeric limitation and to 

solicit site-specific information 

regarding the applicability of the 

numeric effluent limitation to cold 

weather sites and to small sites that are 

part of a larger project. 

On August 24, 2010, the Court issued 

its decision remanding the matter to the 

Agency but without vacating the 

numeric limitation. Subsequently on 

September 9, 2010, the petitioners filed 

an unopposed motion asking the Court 

to reinstate the litigation, hold it in 

abeyance until February 15, 2012, and 

vacate the numeric limitation. On 

September 20, 2010 the Court reinstated 

the litigation and held it in abeyance 

until February 15, 2012, but did not 

vacate the numeric limitation. 

D. Stay of the Numeric Limitation 

On November 5, 2010, EPA issued a 

direct final regulation and a companion 

proposed regulation to stay the numeric 

limitation at 40 CFR 450.22 indefinitely. 

The proposed rule solicited comment 

due no later than December 6, 2010. 

Since no adverse comments were 

received, the direct final rule took effect 

on January 4, 2011. 

Since the numeric portion of the rule 

was stayed, states are no longer required 

to incorporate the numeric turbidity 

limitation and monitoring requirements 

found at § 450.22(a) and § 450.22(b). 

However, the remainder of the 

regulation is still in effect and must be 

incorporated into newly issued permits. 

The purpose of this notice is to solicit 

new data from the public and request 

comment on a number of issues that 

EPA would like to consider in the 

context of establishing numeric effluent 

limitations for construction site 

stormwater discharges. 

III. Review of Treatment Data in EPA’s 

Current Dataset 

A. Approach To Calculating the 

December 2009 Turbidity Limitation 

The December 2009 C&D rule 

established a numeric limitation for 

discharges of turbidity from 

construction sites. The final limitation 

was set at 280 nephelometric turbidity 

units (NTU) based on the application of 

polymer-aided settling, or passive 

treatment. The data used in the 

derivation of this limitation came from 

several construction sites that were 

using polymer-aided settling in 

impoundments or in channel 

applications. EPA’s data represented 

treatment at eight separate construction 

sites located in Washington State, New 

York, and North Carolina. 

The data used in the calculation of the 

December 2009 numeric limitation 

included data from ponds that were 

used to pre-treat stormwater prior to 

chitosan-enhanced sand filtration 

(CESF) active treatment systems (ATS). 

Data representing the final effluent 

leaving CESF had been used in the 

calculation of the November 28, 2008 

proposed C&D rule numeric limitation 

(73 FR 72562), which was based on the 

performance of full CESF. 

EPA considered effluent from the 

CESF pretreatment ponds as 

representing passive treatment, and 

used some such data in the calculation 

of the December 2009 limitation. An 

integral part of CESF and ATS is the 

ability to recirculate pretreated water or 

effluent from the filters back to the 

pretreatment ponds if turbidity levels 

are above pre-established thresholds. 

Although this recirculated water is 

above these thresholds, it may be lower 

in turbidity than the untreated 

stormwater entering the ponds, and/or 

water that is already in the ponds. The 

effect of recirculating water that is lower 

in turbidity than water contained in the 

pretreatment ponds would be to reduce 

the turbidity of the water in the 

pretreatment ponds. Concerns have 

been raised that such recirculation 

represents an additional level of 

‘‘treatment’’ that goes beyond what is 

otherwise understood as ‘‘passive’’ 

treatment. 

B. Passive and Semi-Passive Treatment 

Dataset 

If EPA excludes data from the ATS 

pretreatment ponds, the remainder of 

EPA’s passive treatment dataset used in 

the December 2009 final rule consists of 

data from three passive treatment 

systems. Since promulgation of this 

rule, EPA has received additional 

information and data from several 

sources on the performance of passive 

and semi-passive treatment approaches. 

As discussed below, EPA also had 

additional data in the record regarding 

passive treatment that was not used in 

calculating the December 2009 final 

rule. The following discussion 

summarizes the information and data 

that comprise EPA’s currently reviewed 

dataset of passive and semi-passive 

treatment that is available in the docket. 

EPA continues to receive and review 

additional data as it becomes available. 

EPA may consider these data and any 

data submitted during the public 

comment period and collected by EPA 

in a future rulemaking to correct and 

remove the stay of the numeric turbidity 

limitation. Any data that EPA is 

considering for use in this rule making 

will be placed in the public docket once 

it has been reviewed. 

Steeltown Road and Curley Maple 

Road, North Carolina (DCN 70018 and 

70065). This study evaluated the 

performance of fiber check dams with 

polyacrylamide (PAM) on two mountain 

roadway projects in North Carolina. 

These data were available at the time of 

the December 2009 final rule, but 

additional information on sample 

collection times and turbidity were 

submitted to EPA in 2011 (DCN 70065). 

Orange County, North Carolina 

Skimmer Basin (DCN 70034 and 70065). 

This paper evaluated a skimmer 

sediment basin with PAM at an 

institutional construction project. These 

data were available at the time of the 

December 2009 final rule, but additional 

information on sample collection times 

and turbidity were submitted to EPA in 

2011 (DCN 70065). 

Petersburg airport culvert 

replacement (DCN 70000). This study 

demonstrated the performance of two 

chitosan lactate biopolymer 

formulations in removing turbidity from 

pumped water at the Petersburg, Alaska 

airport. Water was semi-passively 

treated by pumping turbid water from 

one of five culvert locations through a 

cartridge applicator and then into 

sediment traps constructed of filter 

fabric. Additional treatment was 

accomplished by allowing the water to 

exit the trap and flow through a 

vegetated area (called a biofilter). 


pmangrum on DSK3VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 115 

Testing at this site occurred during 

March and April of 2009. Reported air 

temperatures varied between ¥1.0 and 

10 degrees Celsius and reported water 

temperatures varied between ¥0.1 and 

1.0 degrees Celsius during the study, 

demonstrating the effectiveness of 

passive treatment during cold-weather 

conditions. The study did note that 

chitosan lactate dissolution rates were 

slower due to the cold temperatures. 

The study noted that average daily 

turbidity of discharge from the sediment 

trap was 248 NTU, and discharge from 

the biofilter was 102 NTU. Influent 

turbidities were reported as high as 

approximately 5,000 NTU. In order to 

overcome the slower dissolution rate of 

the chitosan lactate due to the cold 

temperatures, additional cartridges were 

installed in order to deliver the 

appropriate dosage. In addition, the 

vendor indicated that a new formulation 

has been developed that dissolves at a 

higher rate specifically for use in colder 

climates. This report also provides 

diagrams showing various forms of 

passive and semi-passive dosing that 

have been developed. Additional 

references describing this project are 

also included in the docket (see DCNs 

70001 and 70002). EPA requests 

comment on whether this dataset 

should be considered representative of 

the BAT technology as described in the 

2009 final rule. 

Water Quality Improvements Using 

Modified Sediment Control Systems on 

Construction Sites (DCN 70063). This 

research project studied three types of 

sediment capture and treatment systems 

at a highway construction project (I– 

485) between 2003 and 2006 in North 

Carolina. The first type of system 

consisted of unlined diversion ditches 

with rock check dams leading to a 

standard sediment trap with a rock dam 

outlet. The second type of system added 

a forebay, porous baffles and PAM 

treatment in the diversion ditches and 

the forebay. The third type of system 

tested was the same design as the 

second system except the rock check 

dam was replaced with a floating outlet 

or skimmer. The author reported that 

the three sediment trapping systems 

with modifications including forebays, 

porous baffles, ditch lining, and PAM 

application had storm weighted average 

turbidity and peak turbidity of 990 and 

1,580 NTU, respectively. 

North Carolina State University 

Typar® Field Test (DCN 70003). North 

Carolina State University (NCSU) 

conducted a field test of the Typar® 

geotextile product at the university’s 

field laboratory. The study evaluated the 

performance of the material in an inchannel application. The tests 

incorporated polyacrylamide to aid in 

sediment removal. Both total suspended 

solids and turbidity were evaluated. The 

study evaluated varying flow rates as 

well as varying sediment loading rates. 

The report contains a considerable 

amount of data. The report indicates 

that the system is expected to meet a 

280 NTU limitation, but points out that 

field testing outside of the field 

laboratory setting, where turbidity and 

total suspended solids (TSS) levels may 

be higher, would provide additional 

insights into performance. 

Other Research at North Carolina 

State University (DCN 70004). 

Researchers at NCSU have conducted 

research on a number of passive and 

semi-passive treatment approaches. 

Examples include fiber check dams with 

PAM, sediment basins and traps with 

PAM, PAM applied to erosion control 

matting down a slope, PAM application 

in pipes and geotextile filter bags with 

PAM. DCN 70004 contains data from a 

number of evaluations. Additional data 

on one of the projects identified in DCN 

70004 is also presented in DCN 70053— 

70060 and 70062. 

North Carolina Department of 

Transportation (NCDOT) (DCN 70005, 

70006). NCDOT conducted a 

demonstration to evaluate the 

performance of a dual biopolymer 

system in removing turbidity. In this 

application, water from culvert sites and 

caissons at bridge construction sites that 

was impounded in a baffled skimmer 

basin was pumped through a manifold 

containing biopolymers. The 

biopolymers dissolve as water is 

pumped through the manifold, and 

mixing occurs in the manifold, which 

aids flocculation. The water then passes 

through a geotextile filter bag, which 

retains the flocculated solids. In this 

demonstration, turbidity in the water 

from the basin was 1,283 NTU, which 

was reduced to below 100 NTU 

following the filter bag. 

StormKlear® (DCN 70007 through 

70013 and 70070 through 70080). 

StormKlear®/HaloSource® provided 

information regarding a number of sites 

using both passive and semi-passive 

dosing of a dual biopolymer system. 

Sites described were Annapolis, 

Maryland (DCN 70007), Austin, Texas 

(DCN 70008), Beaverton, Oregon (DCN 

70009), Griffin, Georgia (DCN 70010), 

Raleigh, North Carolina (DCN 70011), 

Memphis, Tennessee (DCN 70011), 

Jacksonville, North Carolina (DCN 

70011), Birmingham, Alabama (DCN 

70011), Tampa, Florida (DCN 70012), 

Tennessee (DCN 70013), Huntersville, 

North Carolina (DCN 70070), Hanover, 

Maryland (DCN 70071), Apex, North 

Carolina (DCN 70072), Bonita Springs, 

Florida (DCN 70073), Staten Island, 

New York (DCN 70074), Cabarrus 

County, North Carolina (DCN 70075), 

Anne Arundel County, Maryland (DCN 

70076), Cartersville, Georgia (DCN 

70077), Central, South Carolina (DCN 

70078), Fairview, North Carolina (DCN 

70079) and Lavonia, Georgia (DCN 

70080). The range of turbidity values 

reported at these sites is presented in 

Table 1. 

TABLE 1—RANGE OF TURBIDITY VALUES REPORTED IN DUAL BIOPOLYMER FIELD TRIALS

Site Untreated NTU Treated NTU 

Annapolis, MD ................................................................................................................................. 300–400 .................... 15. 

Austin, TX ........................................................................................................................................ 598 ............................ 10.5–117. 

Beaverton, OR ................................................................................................................................. 42–44 ........................ 14. 

Griffin, GA ........................................................................................................................................ 2,189 ......................... 21.1–433. 

Raleigh, NC ..................................................................................................................................... 2,500–3,000 .............. 14. 

Memphis, TN ................................................................................................................................... 1,200 ......................... 20. 

Jacksonville, NC .............................................................................................................................. 300 ............................ 15. 

Birmingham, AL ............................................................................................................................... 1,500 ......................... 20. 

Tampa, FL ....................................................................................................................................... Not Reported ............. <1. 

Huntersville, NC ............................................................................................................................... 950 ............................ 425. 

Hanover, MD .................................................................................................................................... 570 ............................ <50. 

Apex, NC ......................................................................................................................................... 3,787 ......................... 297 (1.4 after basin). 

Bonita Springs, FL ........................................................................................................................... 162–187 .................... 3.2–43. 

Staten Island, NY ............................................................................................................................. 1,057 ......................... 5–45. 

Cabarrus County, NC ...................................................................................................................... 1,195 ......................... 42. 


pmangrum on DSK3VPTVN1PROD with NOTICES
116 Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 

1 In December 2011, the California Superior Court 

invalidated the California numeric standard of 500 

NTU, which applied to a subset of construction 

projects, because the state did not evaluate 

performance data from available technologies under 

a variety of site conditions. Construction projects 

subject to the standard did not have ‘‘reasonable 

assurance that the technologies are capable of 

achieving the turbidity NEL (numeric technology 

based effluent limitation).’’ Decision at 16; 

California Building Industry Association v. State 

Water Resources Control Board, Case No. 34–2009– 

800000338 (Sacramento Superior Court) December 

2, 2011. See DCN 70086. 

2The term ‘‘passive sand filter’’ in this context is 

used to describe an in-ground filter constructed by 

placing sand and gravel into an excavated area. The 

filter receives surface discharge from up-slope 

sediment controls which is distributed across the 

filter surface using distribution pipes. Water flows 

down through the filter bed and is collected by an 

underdrain system where it is conveyed downslope. All flow in this application is by gravity. The 

system did not incorporate any pumps or any 

treatment chemicals. A passive sand filter differs 

from the sand filters which are used as part of 

CESF, which are operated by a programmable logic 

controller or onsite personnel, are pressurized and 

operate at much higher flowrates, among other 

differences. 

TABLE 1—RANGE OF TURBIDITY VALUES REPORTED IN DUAL BIOPOLYMER FIELD TRIALS—Continued 

Site Untreated NTU Treated NTU 

Anne Arundel County, MD ............................................................................................................... 547 ............................ 120. 

Cartersville, GA ................................................................................................................................ >4,000 ....................... 51. 

Central, SC ...................................................................................................................................... 687 ............................ 32. 

Fairview, NC .................................................................................................................................... >4,000 ....................... 731 (131 after basin). 

Lavonia, GA ..................................................................................................................................... >4,000 ....................... 32.8. 

ALPURT B2 Motorway Construction 

Project (DCN 70049). The Auckland, 

New Zealand Regional Council 

evaluated the use of polyaluminum 

chloride (PAC) to reduce sediment 

discharges from a motorway 

construction project. A rainfall-activated 

dosing system was used to deliver PAC 

prior to settling in a sediment basin. 

Samples were analyzed for TSS, particle 

size distribution and dissolved 

aluminum. This study did not evaluate 

reductions in turbidity. 

ALPURT and Greenhihte Trials (DCN 

70067). The Auckland, New Zealand 

Regional Council conducted trials using 

alum, PAC and PAM at several sites. 

The study evaluated both rainfallactivated liquid chemical dosing 

systems as well as solid forms. This 

study evaluated reductions in TSS, but 

not turbidity. 

Bluffs Community Baffle Grid System 

(DCN 70050). This project, located in 

the metropolitan Atlanta, Georgia area, 

was a residential construction project. A 

passive treatment system was utilized 

consisting of a grit pit followed by a 

polymer mixing chamber. The water 

then flowed into another grit pit and 

then into a baffle grid system. Polymer 

was dosed using polymer floc logs. 

Polymer was also applied to exposed 

soils up-slope of the treatment system. 

This system produced an average 

treated turbidity of 18 NTU, according 

to the study authors. The attached data 

file shows a range of turbidity after the 

baffle grid ranging from 1.0 to 703 NTU. 

Cleveland Municipal Airport, 

Cleveland, Tennessee (DCN 70085). 

This site is a multi-year construction 

project that started in 2009. The site 

utilizes passive treatment including 

ditches lined with jute matting with 

PAM and sediment basins. Monitoring 

is conducted after the sediment basins 

as well as in-stream both upstream and 

downstream of the construction site. 

Only limited monitoring data was 

available for this site. The turbidity 

reported in effluent at the outfalls after 

implementation of the PAM treatment 

ranged from 23 to 280 NTU. 

C. Additional Data 

At the time of this notice, only one 

state (California) has a numeric effluent 

limitation for discharges from 

construction activities that applies to a 

subset of construction sites statewide. 

Other sites in the state are subject to 

monitoring requirements and action 

levels.1 Between July 1, 2010 and June 

20, 2011, permittees reported 735 daily 

average turbidity values. The range of 

these daily average turbidity values was 

zero to 1,572 NTU with a median value 

of 42 NTU (see DCN 70051). EPA did 

not obtain information about the 

individual sites and treatment systems 

(such as detailed site plans, SWPPPs, 

etc.), and has not evaluated the utility 

of this data in the context of establishing 

effluent guidelines. EPA has not 

evaluated whether any of these facilities 

were subject to numeric discharge 

standards for turbidity. 

As described in the December 2009 

final rule preamble, Warner et al. 

evaluated several innovative erosion 

and sediment controls at a full-scale 

demonstration site in Georgia. In this 

project, polymers or flocculants were 

not utilized, but instead a 

comprehensive system of erosion and 

sediment controls were designed and 

implemented to mimic pre-developed 

peak flow and runoff volumes with 

respect to both quantity and duration. 

The system included perimeter controls 

that were designed to discharge through 

multiple outlets to a riparian buffer, 

elongated sediment controls (called seep 

berms) designed to contain runoff 

volume from 3- to 4-inch storms and 

slowly discharge to down-gradient 

areas, multi-chambered sediment basins 

designed with a siphon outlet that 

discharged to a sand filter, and various 

other controls. Monitoring conducted at 

the site illustrates the effectiveness of 

these controls. For one particularly 

intense storm event of 1.04 inches (0.7 

inches of which occurred during one 27- 

minute period), the peak sediment 

concentration monitored prior to the 

basin was 160,000 mg/L of TSS while 

the peak concentration discharged from 

the passive sand filter 2 after the basin 

was 168 mg/L. Effluent turbidity values 

ranged from approximately 30 to 80 

NTU. Using computer modeling, it was 

shown that discharge from the sand 

filter, which flowed to a riparian buffer, 

was completely infiltrated for this event. 

Thus, no sediment was discharged to 

waters of the state from the sand filter 

for this event. For another storm event, 

a 25-hour rainfall event of 3.7 inches 

occurred over a two-day period. Effluent 

turbidity from one passive sand filter 

during this storm ranged from 

approximately 50 to 375 NTU, with 20 

of the 24 data points below 200 NTU. 

For a second passive sand filter, effluent 

turbidity ranged from approximately 50 

to 330 NTU, with nine of 11 data points 

below 200 NTU. In the Warner et al. 

study low levels of turbidity in 

discharges were achieved without 

relying on chemical flocculants or 

polymers or pumping of water. 

Although these data were available to 

EPA at the time, EPA did not use the 

Warner et al. data in calculating the 

limitation contained in the December 

2009 final rule because the site did not 

use polymers. EPA requests comment 

on whether the Warner et al. data, data 

from passive sand filters in general as 

described by Warner et al., and data 

from sites not using polymers or 

flocculants should be used in evaluating 

the feasibility of a numeric effluent 

limitation and whether these data 

should be considered representative of 


pmangrum on DSK3VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 117 

the BAT technology as described in the 

2009 final rule. 

IV. Solicitation of Data and Comments 

on Numeric Effluent Limitations for 

Turbidity 

The following presents the issues and 

areas where EPA is soliciting feedback, 

data and information. 

A. Control of Turbidity—Effectiveness, 

Costs and Feasibility of Different 

Technologies 

On November 28, 2008 EPA issued a 

proposed rule that would have 

established a numeric effluent 

limitation for turbidity based on the 

application of what is termed active or 

advanced treatment, or ATS, 

specifically chitosan-enhanced sand 

filtration (CESF). ATS consists of a 

variety of technologies, the two most 

prevalent being CESF and 

electrocoagulation. The basic premise 

behind CESF is to collect the 

stormwater in a pond or basin, 

withdraw the water from the basin 

(using pumps), add a treatment 

chemical (in this case chitosan, 

although the technology is adaptable to 

other treatment chemicals), and remove 

the flocculated solids using filtration. 

Pretreatment with a treatment chemical 

(such as chitosan) is frequently used to 

reduce the turbidity of the stormwater 

withdrawn from the pond or basin to a 

range that will allow for efficient 

filtration. This is frequently done in 

dedicated pretreatment cells or tanks, 

but the configuration can depend on 

requirements specified by the regulatory 

agency or the operator. CESF typically 

incorporates a programmable logic 

controller to monitor turbidity and pH 

of the treated water continuously or 

during some specified time interval, and 

valves can be actuated automatically by 

the controller to recycle the treated 

water back to the pretreatment cells or 

storage pond if the discharge does not 

meet pre-established thresholds. 

Electrocoagulation does not use a 

polymer or treatment chemical, but 

rather uses an electrical process to 

destabilize the particles. Agglomerated 

particles are removed by settling and/or 

filtration. ATS, based on information 

available to EPA on the performance of 

CESF, appears capable of producing 

very low turbidity (generally less than 

50 NTU, and in many cases less than 5 

NTU) in treated stormwater from 

construction sites. Performance can be 

further enhanced by polishing the 

filtered water in bag or cartridge filters. 

EPA requests comment on this 

description of ATS. 

Costs for ATS systems include 

equipment rental (pumps, filters, 

generators and control equipment), fuel, 

chemicals, labor, management of 

residuals, piping, and miscellaneous 

consumables (residual polymer test kits, 

filtration media, etc.) and data 

management and reporting. A stabilized 

area (such as a gravel pad) may be 

necessary in some cases. In colder 

climates, consideration of measures to 

prevent freezing of equipment may also 

be necessary. The requirement to store 

water in ponds and to pretreat water can 

add costs. Also, managing dewatering of 

a series of large impoundments on some 

sites may be complicated, particularly 

during extended periods of 

precipitation. The costs of large ponds 

may be offset to some extent if they are 

converted to post-construction 

stormwater water-quality or floodcontrol ponds. This is frequently 

accomplished by removing the 

accumulated sediment captured during 

the construction phase and altering the 

outlet structure of the basin to achieve 

the water quality and peak discharge 

rate control desired for the postdeveloped condition. This can result in 

considerable cost savings for the postconstruction ponds, since significant 

costs are associated with excavation of 

the basins. However, recent trends 

toward use of decentralized stormwater 

management may be a disincentive 

toward utilizing large ponds (although 

the need for flood control ponds and 

ponds to control stream channel erosion 

may still exist). Practices such as 

bioretention, porous pavement, 

infiltration systems and harvest and use 

systems may replace, to some extent, 

centralized conveyance and stormwater 

detention and retention ponds. 

However, if decentralized controls are 

used for postconstruction stormwater 

management, then basins used during 

the construction phase may not need to 

be converted for post-construction use. 

In these cases, the construction phase 

basins may need to be filled in, at 

additional expense to the developer. In 

some instances, this may provide space 

where additional structures, parking or 

other amenities can be placed, which 

may provide a benefit to the developer. 

Passive treatment systems (PTS) in 

the context of construction site 

stormwater management are practices 

that do not rely on computerized 

systems with pumps, filters and realtime controls but do incorporate a 

treatment chemical to aid in sediment 

and turbidity removal. Passive treatment 

could include pumps where they are 

necessary to move water around the 

construction site, and pumping may be 

integral to properly dosing the water 

with treatment chemicals in some cases. 

When pumps are utilized to pump the 

water through a manifold or other 

apparatus to dose the chemical, this 

type of treatment has been characterized 

by the industry as semi-passive 

treatment. In passive treatment, polymer 

can be placed in channels that convey 

water on the construction site, or they 

may be used prior to basins or other 

practices (such as a baffle-grid, inground sand filter or a geotextile filter 

bag) that allow for settling and/or 

filtration of the flocculated material. 

Treatment chemicals, either in solid or 

liquid forms, can be applied at various 

locations on the site. Common PTS 

include fiber check dams with PAM and 

sediment basins dosed with PAM as 

described by McLaughlin (see DCNs 

70018, 70034 and 70063). The 

Auckland, New Zealand Regional 

Council also described a PTS that 

utilized a rainfall-actuated system to 

deliver liquid chemical (see DCN 70049 

and 70067). Minton (see DCN 70069) 

described a ‘‘pump and treat’’ system 

whereby water was pumped from a 

basin, a treatment chemical was added, 

and the water was allowed to settle in 

dedicated treatment cells. Water can be 

re-circulated with the pump and 

additional chemical added if the settled 

water does not meet specifications. As 

stated above, the term semi-passive 

treatment has been used to describe 

practices that utilize pumped water to 

dose the chemical, or applications 

where the water is first held in a basin 

or other impoundment and withdrawn 

under more controlled conditions for 

subsequent treatment. Recent 

improvements to PTS incorporate the 

use of two polymers (see DCNs 70006– 

70013, 70070–70080), which can be 

placed in a manifold or in a channel. 

The use of baffles and floating outlets or 

‘‘skimmers’’ on basins are frequently 

incorporated as part of PTS, and 

directing treated water to vegetated 

areas or ‘‘biofilters’’ can also provide 

additional sediment and turbidity 

removal prior to discharge. EPA 

requests comment on these descriptions 

of ‘‘passive’’ and ‘‘semi-passive’’ 

treatment systems and comments on 

what practices should be considered 

representative of the BAT technology as 

described in the 2009 final rule. 

The performance of PTS varies based 

on the type of system, the method used 

to dose chemicals, as well as other 

factors. The performance of simple PTS 

appears to be sensitive to the type and 

frequency of maintenance and system 

configuration, as well as the intensity 

and duration of storm events. An 

advantage of simple PTS, such as fiber 

check dams w/PAM, is that they are 


pmangrum on DSK3VPTVN1PROD with NOTICES
118 Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 

very inexpensive and can be easily 

incorporated into sites at multiple 

locations and do not require large ponds 

for storage prior to treatment. A 

disadvantage may be that achieving a 

consistent level of performance may be 

more difficult due to variations in storm 

flows and sediment loads and little 

control over dosage rates. The data 

available to EPA does show high levels 

of turbidity in discharges for some 

events, indicating that simple passive 

treatment systems may not perform well 

during larger and/or more intense storm 

events. Data collected at a construction 

site in North Carolina that used passive 

treatment measured peak turbidity in 

excess of 40,000 NTU during an intense 

storm event (see DCN 70064.3). 

Semi-passive approaches, which first 

hold the water in a basin, tank or 

impoundment and then release water 

either by gravity or with a pump to 

provide dosing, appear to be capable of 

providing lower, and perhaps more 

consistent, turbidity levels due to 

dampening of the storm flows by the 

basins. An advantage of semi-passive 

approaches is that since the water is 

withdrawn by pumping (although semipassive dosing can be accomplished 

using gravity flow in certain cases), 

flowrates and dosing rates can be more 

easily controlled, allowing for more 

consistent and likely better 

performance. Since the water is 

withdrawn from the storage pond and 

dosed at a more controlled rate, the 

large variability and poorer performance 

that may occur under some 

precipitation conditions with simple 

passive treatment can potentially be 

avoided. A disadvantage may be that the 

stormwater must first be stored in 

ponds, tanks or other impoundments in 

order to provide a controlled release. As 

with ATS, these storage requirements 

can add costs and additional operational 

considerations to address, particularly 

during extended periods of 

precipitation. As described earlier, these 

costs may be offset to some extent 

depending on the nature of postconstruction stormwater requirements 

in place. 

An integral component of ATS and 

PTS is the use of a treatment chemical 

to aid in removal of sediment and 

turbidity. However, data presented by 

Warner and Collins-Camargo (see DCN 

70052) indicates that a comprehensive 

suite of erosion and sediment controls is 

also capable of producing treated 

stormwater with low levels of turbidity. 

EPA has little data on which to base a 

numeric limitation on these types of 

practices as this level of management 

does not appear to be typical at most 

construction sites. 

EPA is soliciting data and information 

on the costs, effectiveness and 

feasibility of different technologies to 

control TSS, settleable solids, 

suspended sediment concentration and 

turbidity in construction site stormwater 

discharges. EPA is also soliciting data 

on other water quality parameters, such 

as pH, nutrients and metals. EPA is 

especially interested in receiving data 

on the performance of passive and semipassive treatment approaches. Data 

collected both before the treatment or 

management practice (influent data) as 

well as data after the treatment or 

practice (effluent concentration) would 

be useful. EPA already has a large 

dataset on the performance of ATS in 

removing turbidity, but additional data 

on the costs of ATS would potentially 

be useful to EPA. To be most useful, 

EPA requests that treatment 

performance data represent multiple 

discharge events, that samples are 

collected over regular intervals over the 

course of the event (or the discharge), 

and that the data contain, if available, 

the following descriptive information: 

• Site information, such as project 

size, project type (residential, 

commercial, road/highway, etc.), 

location, phase of construction (e.g., 

before, during or after grading, site 

stabilization, etc), etc.; 

• Sample date(s) and time(s) of 

collection and date(s) and time(s) of 

analysis; 

• Sample type (grab sample, flow or 

time-weighted composite, continuous 

turbidity measurement, etc.); 

• Analytical method and/or type of 

field instrument used to measure the 

parameter; and 

• Description of the treatment 

technology, including method of 

treatment chemical dosing utilized. 

Additional information that would be 

useful in evaluating these data includes: 

• Estimates of the amount and 

intensity of precipitation for the time 

preceding and/or during sampling 

events; 

• Drainage characteristics 

(predominant soil types/textures, 

drainage area, estimate of the quantity 

or percent of the drainage area that is 

disturbed); 

• The ambient air temperature when 

the data is being collected; 

• Date of last calibration if a field 

instrument was used; and 

• Descriptions of any quality 

assurance/quality control procedures 

implemented for the data collection 

activity. 

In order to be most useful, data on 

costs should include: 

• Installation costs (both material and 

labor); 

• Operation and maintenance burden 

(in terms of labor hours and/or costs); 

• Quantity, cost and frequency of 

treatment chemical use; and 

• Other costs (residuals management, 

consumables, energy use, etc.). 

EPA requests comment on other 

factors EPA should consider other that 

those listed above in evaluating 

treatment performance data and what 

metadata commenters consider 

important to consider in the context of 

establishing effluent limitations. 

B. Sampling and Data Collection— 

Procedures and Protocols To Ensure 

Representativeness of Data; Differences 

in Analytical Equipment 

EPA is aware that there are several 

issues associated with collecting 

turbidity data in the field at 

construction sites. These issues are 

associated with sampling equipment 

limitations, turbidimeter limitations, 

differences between turbidity measuring 

equipment, and sample handling and 

analysis. The following discussion 

presents information that EPA is aware 

of with respect to these issues and 

solicits data and comment on these 

issues. These issues relate both to 

collecting samples for the purposes of 

establishing effluent limitations as well 

as collecting samples for compliance 

determination. 

Sampling Equipment Limitations 

Collecting samples of stormwater at 

construction sites can be accomplished 

using either automated equipment or by 

collecting grab samples. Automated 

equipment typically requires the use of 

a flow measuring device and an 

automated sampler. Flow measurement 

devices require that a weir, flume or 

other structure be installed in the 

conveyance that has a known rating 

curve (discharge vs. flow depth), or that 

a custom rating curve be developed for 

open channels based on surveyed 

channel geometry that can be used to 

estimate flow as a function of depth of 

water. Automated samplers can be set 

up to collect samples after a 

predetermined amount of flow has 

passed through the measuring device 

(flow-weighted) or after a predetermined 

amount of time has passed (timeweighted). In either case, the sample 

collection interval must be selected 

such that sufficient samples are 

collected over the course of the 

hydrograph to adequately characterize 

the discharge. This is frequently 

difficult, as it is not known in advance 

how much precipitation and flow will 

occur. If the sample collection interval 

is set too low, then the sampler may fill 

up before the end of the event. In this 


pmangrum on DSK3VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 119 

case, a portion of the hydrograph may 

not be sampled. If the interval is set too 

high, then too few samples may be 

collected to adequately characterize the 

event. Given the variability in 

stormwater flows, this may make the 

use of automated sampling challenging. 

Grab samples are easier to collect than 

automated samples. However, collecting 

grab samples requires that someone be 

physically present on the site. Given the 

variable nature of storm events and that 

those events can occur during all hours 

of the day, collecting grab samples to 

characterize performance can also be 

challenging. This is particularly true 

when the site is not located in close 

proximity to field offices of the 

sampling personnel. 

In the context of characterizing 

performance for establishing effluent 

limitations, both grab samples and 

automated samples are potentially 

useful. Generally, EPA believes that 

samples used to characterize 

performance should be collected 

regularly over the course of the event in 

order to capture variability in flows and 

associated pollutant parameters. This is 

particularly true in the case of passive 

treatment, which does not involve 

capture of the water in a pond or basin 

for controlled release, so that one would 

expect greater variability in sampled 

parameters. For treatment of water 

discharged in a controlled rate from a 

pond, one would expect less variability 

in flows and performance, so less 

frequent sample collection would likely 

be necessary in order to adequately 

characterize performance. 

Turbidimeter Limitations 

Samples collected for turbidity can be 

measured in the field using a hand-held 

turbidimeter, or can be sent to a 

laboratory for analysis using a benchtop 

turbidimeter. Both methods are simple 

and inexpensive. However, 

turbidimeters only operate within 

specific ranges. The high-end of the 

range is typically around 1,000 NTU or 

more. Samples with high amounts of 

turbidity may need to be diluted in 

order for the turbidity of the sample to 

be within the operating range of the 

instrument. This is a potential source of 

error, especially if done in the field. 

Another method for measuring turbidity 

is to use an in-situ meter coupled to a 

datalogger. In-situ meters can be 

programmed to record turbidity 

continuously at some specified time 

interval (such as every 15 minutes). As 

with other instruments, in-situ 

turbidimeters typically operate within a 

specific range. With these instruments, 

turbidity above the measurement range 

of the instrument cannot be determined, 

since a physical sample is not collected. 

This is a potential source of error, 

particularly during periods of peak 

flows where turbidity may be very high. 

This is a downside of in-situ meters 

because an average turbidity for an 

event cannot be determined if some of 

the data exceeds the measurement range 

of the instrument. In these cases, the use 

of both an in-situ meter as well as 

collection of a physical sample during 

peak flow periods may be necessary to 

accurately determine the average 

turbidity for the event. In-situ meters are 

also susceptible to failure, such as from 

battery failure or a piece of debris 

obscuring the detector. 

Different types of turbidimeters may 

provide different measurements of 

turbidity for the same sample. This is 

due to differences in light sources and 

differences in the orientation of the light 

source with respect to the detector. In 

addition, while turbidity measured in 

NTUs is the standard contained in 

EPA’s methods, turbidity can also be 

measured in other units, such as 

formazin turbidity units (FTUs). While 

EPA believes that NTUs are the 

appropriate units in the context of 

effluent limitations for construction site 

stormwater, EPA solicits comments on 

the types of equipment that should be 

allowable and other considerations 

related to differences in measurement 

equipment and measurement units. 

Sample Handling and Analysis 

EPA notes that some of the data in 

EPA’s dataset did not follow the sample 

preservation protocols contained in 

EPA’s approved analytical methods. 

EPA method 180.1 states that turbidity 

samples should be immediately 

refrigerated or iced to 4°C and analyzed 

within 48 hours. EPA is aware that 

many of the samples collected by 

researchers at North Carolina State 

University and described in DCNs 

70004, 70018, 70034, 70053, 70054 and 

70065 were collected using automated 

samplers, and that the samples were not 

analyzed within 48 hours or refrigerated 

or iced. In many instances, samples 

were analyzed several days or weeks 

after collection. While EPA notes the 

deviation from approved methods, EPA 

does not believe that this deviation 

would produce appreciable changes in 

measured turbidity in these cases. The 

sample refrigeration and analytical 

timeframe guidelines are intended to 

minimize changes in turbidity that 

would result due to microbial 

decomposition of solids in the sample. 

Since EPA expects little organic 

material to be present in samples of 

stormwater runoff from construction 

sites since the solids are primarily 

composed of inert soil particles, EPA 

would not expect biological activity to 

appreciably change the turbidity of the 

samples. EPA does note that since these 

samples incorporated polyacrylamides, 

some additional flocculation could 

occur in the sample bottles during the 

time period between collection and 

analysis or during transport from the 

field to the laboratory, if residual or unbound polyacrylamide was present in 

the sample. EPA solicits comment on 

the appropriateness of using data from 

samples not analyzed within 48 hours 

or otherwise not in compliance with 

established analytical methods in the 

context of a future regulation. 

EPA also notes that the samples 

collected by researchers at North 

Carolina State University were allowed 

to settle for approximately 30 seconds 

after mixing before a subsample was 

collected and analyzed for turbidity. 

EPA understands that this 30-second 

settling period after mixing was to allow 

large flocculated particles to settle, since 

analyzing turbidity of a sample that 

contains large agglomerates may prevent 

the turbidity meter from producing a 

stable reading or may underestimate 

turbidity of the sample. The EPA 

approved sampling method does not 

describe an appropriate period of time 

between mixing of the sample bottle and 

collection of the subsample for analysis. 

As described in EPA’s method 180.1 for 

measuring turbidity, the approved 

analytical procedure is ‘‘Mix the sample 

to thoroughly disperse the solids. Wait 

until air bubbles disappear then pour 

the sample into the turbidimeter tube. 

Read the turbidity directly from the 

instrument scale or from the appropriate 

calibration curve.’’ (see DCN 70083), 

The method states that ‘‘The presence of 

floating debris and coarse sediments 

which settle out rapidly will give low 

readings. Finely divided air bubbles can 

cause high readings.’’ Floating debris 

and course sediments and finely 

divided air bubbles are therefore 

considered sources of interference when 

measuring turbidity. The practice 

utilized by researchers at North Carolina 

State University of allowing mixed 

sample bottles to sit for 30 seconds 

before collecting the subsample for 

analysis, which would allow any course 

sediments to settle, may be an 

appropriate means of addressing 

possible interferences due to the 

presence of large particles. EPA also 

acknowledges that allowing the sample 

to settle prior to collecting the 

subsample for analysis may result in 

fewer particles generally being present 

in the subsample and thus an artificially 

low turbidity reading. EPA solicits 


pmangrum on DSK3VPTVN1PROD with NOTICES
120 Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 

comment on the appropriateness of 

using turbidity data where a sample was 

allowed to settle for 30 seconds (or some 

other time period) after mixing before 

collection of the subsample for analysis 

for purposes of evaluating the 

performance of technologies and for 

compliance purposes and the expected 

magnitude of the effects of varying 

settling time on observed turbidity 

values. 

EPA understands that the subsamples 

for TSS were collected by the 

researchers and analyzed immediately 

after mixing. As a result, there are 

certain cases where particular samples 

in these data had TSS concentrations (in 

mg/L) that would appear inconsistent 

when compared to the corresponding 

turbidity measurements (in NTU) since 

the large particles could be present in 

the TSS subsample. EPA notes that the 

ratios of TSS to turbidity for some 

samples are much higher than for other 

samples, which EPA believes can be 

attributed to the 30-second settling time 

prior to collection of the turbidity 

subsample. EPA welcomes comments 

on this topic. 

In the context of compliance 

demonstration, the specifics of a 

particular site (such as the location of 

the site, the number of discharge points, 

proximity of discharge points, 

accessibility of discharge points, etc.) 

are important considerations in 

determining the type of sample to be 

collected. Generally, both automated 

samples and grab samples are 

potentially useful for compliance 

determinations. However, the inherent 

limitations with sampling equipment 

and equipment malfunctions may be 

important considerations. With grab 

samples, equipment limitations and 

equipment malfunctions are not of 

concern. 

EPA solicits comment on the 

appropriate methods for sample 

collection in the context of both 

compliance sampling and analytical 

sampling for the purpose of setting 

limits for a turbidity effluent limitation 

for construction site stormwater 

discharges. EPA recognizes that logistics 

and cost are important considerations, 

and would like to better understand the 

potential costs and challenges of sample 

collection and analysis in these cases. 

C. Effect of Storm Size, Intensity and 

Duration of Precipitation on 

Performance of Passive Treatment 

In establishing effluent guidelines and 

new source performance standards, 

proper operation of the candidate best 

available technology economically 

achievable (BAT) and best available 

demonstrated control technology 

(BADCT) should result in meeting the 

numeric limitation a very high 

percentage of the time. In the case of 

industrial wastewater, treatment 

systems typically perform well within a 

range of flowrates and influent pollutant 

concentrations, and systems typically 

operate within these ranges. Due to 

variations in manufacturing production 

cycles, the flowrates and pollutant 

concentrations in wastewater can vary 

over the course of a day. Industrial 

wastewater treatment systems typically 

incorporate equalization to dampen 

these diurnal variations in flowrates and 

pollutant concentrations. This 

dampening assures that high flows and/ 

or pollutant loads do not overwhelm the 

treatment system, or that low flows and/ 

or pollutant loads do not compromise 

unit processes. 

This same concept applies to 

stormwater treatment. Since 

precipitation is a stochastic process, 

there can be variation in stormwater 

flowrates and sediment loads during the 

course of a given precipitation event. 

Data available to EPA indicates that 

passive treatment with limited storage 

may perform well for some storm 

events, but that larger and/or more 

intense storm events may degrade the 

performance of these systems. The 

likely reasons for a decrease in 

performance include inadequate 

treatment chemical dosing during 

periods of higher flows, exhausting the 

treatment chemical during larger and/or 

longer storm events, high sediment 

loads during intense periods of 

precipitation that overwhelm the 

systems, and short-circuiting/ 

overtopping of controls. These 

occurrences are difficult to address as 

they occur on construction sites in the 

context of passive treatment, which is 

not based on a high level of operator 

involvement. 

A potential shortcoming of EPA’s 

current dataset on passive treatment is 

that much of the data was collected 

during smaller storm events. EPA has 

little data available on the performance 

of this type of flow-through passive 

treatment during larger and/or more 

intense storm events, but the limited 

data available indicate that the 

performance of simple passive treatment 

approaches may not be as good for these 

events. The candidate BAT/BADCT 

should be capable of meeting the 

limitation up to whatever cutoff is 

established for the limitation. In the 

2009 rule, the compliance storm event 

was the 2-year, 24-hour storm event (see 

Section IV.D for additional discussion of 

storm event exemptions). 

EPA does not expect this concern to 

arise with treatment that first holds the 

water in a pond, basin or impoundment. 

Impounding the water has two primary 

benefits for subsequent treatment— 

equalization of flows and reduction/ 

dampening of sediment/turbidity levels. 

The amount of sediment and turbidity 

mobilized during a storm event can vary 

greatly, depending on factors such as 

storm intensity, storm duration, soil 

type and composition, slopes of the 

contributing watershed, extent of soils 

exposed, and the extent and nature of 

construction activities occurring. When 

water is held in a basin, a significant 

portion of the settleable materials would 

be expected to be removed. When water 

is withdrawn for subsequent treatment, 

one would expect much lower 

variability in the amount of turbidity 

over the course of the treatment period. 

D. Exemptions—Design Storm Depth vs. 

Intensity 

The December 2009 final rule 

exempted discharges from compliance 

with the turbidity limitation on days 

where precipitation exceeded the local 

2-year, 24-hour storm depth. The 

rationale for this exemption was that 

large storm events would potentially 

overwhelm the passive treatment 

systems, making compliance with the 

limitation difficult. If an impoundment 

is used to store water prior to treatment, 

a total storm depth may be an 

appropriate compliance threshold since 

impoundments are typically designed to 

store a certain quantity of water. Runoff 

in excess of that volume would either 

bypass storage or be discharged through 

an overflow riser or over a spillway. 

However, both storm depth and storm 

intensity may be important drivers for 

system performance and appropriate 

compliance thresholds for simple inline passive treatment systems. Total 

storm depth (and the total volume of 

stormwater passing through the passive 

treatment system) is an important driver 

of performance because the amount of 

treatment chemical available in a simple 

passive treatment application is limited 

(unless more is applied during the 

event). At some point, available 

treatment chemical may be exhausted 

and treatment performance would be 

expected to decline. Storm intensity 

may be a much more important driver 

of performance of in-line simple passive 

systems than storm depth. During high 

intensity rainfall periods, which occur 

frequently in many parts of the country, 

sediment detachment and mobilization 

can be significant due to the high energy 

of the raindrops. This high level of 

sediment mobilization, coupled with 

flashy flows through conveyances, can 

deposit large quantities of sediment in 

passive treatment systems and flowrates 


pmangrum on DSK3VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 121 

can exceed the dosing capacity of these 

simple systems. Therefore, EPA solicits 

data indicating what critical storm 

intensity would render simple passive 

treatment systems ineffective. In 

addition, any compliance threshold tied 

to storm intensity would optimally 

specify both storm intensity as well as 

a duration over which that storm occurs. 

For example, a storm may have a peak 

five-minute intensity of two inches per 

hour, but if the storm only lasted for five 

minutes, then the total amount of runoff 

would be small. In addition, optimally, 

EPA would specify how long after the 

intensity threshold has been exceeded 

the site would qualify for an exemption 

from the limitation (e.g., for the rest of 

the day, only during the period when 

the peak storm intensity had been 

exceeded, for one hour after the peak 

storm intensity had been exceeded, 

etc.). EPA solicits data and information 

on what would be appropriate 

exemption criteria. 

With semi-passive or ATS 

approaches, storm intensity would 

likely not be as critical, given that the 

water is first held in a basin or 

impoundment. Therefore, an exemption 

based on total storm depth may be 

appropriate, since the standard could 

specify a storage volume and a 

drawdown time (e.g., basins must be 

sized to store runoff from the 2-year, 24- 

hour storm and the treatment system 

sized to dewater the entire storage 

volume in 48 hours). Any flow going 

over the riser or emergency spillway 

during that time period could be exempt 

from the limitation. 

E. Use of Treatment Chemicals, 

Disposal and Toxicity Concerns 

ATS, passive and semi-passive 

treatment practices on construction sites 

utilize a variety of treatment chemicals. 

Common treatment chemicals include 

chitosan, polyacrylamides (PAM), alum, 

polyaluminum chloride (PAC), 

diallydimethyl-ammonium chloride 

(DADMAC) and gypsum. These 

chemicals are used to help destabilize 

and flocculate soil particles, allowing 

for removal by filtration, adhesion or 

settling. Additional chemicals may be 

used to adjust pH or other water 

chemistry parameters. Treatment 

chemicals in use on construction sites 

have varying toxicity profiles. EPA has 

limited data on acute and chronic 

toxicity of these treatment chemicals in 

the context of their use to treat 

construction site stormwater; however it 

is generally known that unbound 

cationic chemicals can exhibit 

mechanical lethality to some species in 

some instances. The degree of toxicity of 

any treatment chemical is a function of 

the organism, chemical formulation, 

charge density, dose rate, exposure time, 

and degree of sediment/turbidity in the 

receiving environment. Some states 

have approved specific chemicals and 

formulations for use on construction 

sites. Some stakeholders raised concerns 

about the toxicity of the treatment 

chemicals in comments received on the 

November 2008 proposed rule. EPA is 

also aware that some states do not 

currently allow addition of any 

treatment chemicals to stormwater on 

construction sites. In these cases, it is 

unclear how permittees would comply 

with a numeric limitation, although as 

stated earlier, a comprehensive suite of 

conventional practices was 

demonstrated to produce low turbidity 

in discharges at the project described in 

Warner et al. 

As mentioned above, stakeholders 

have raised concerns regarding acute 

and chronic aquatic toxicity effects due 

to the use of chemicals in treatment of 

construction site stormwater. The 

concerns are related to the lack of 

control of dosage rates in passive 

treatment, operator error in passive, 

semi-passive and ATS applications, and 

other accidental or unintended releases. 

Anionic granular and water-based PAMs 

that are used in surface water treatment 

applications (such as for managing 

construction site stormwater and in 

agricultural applications) are generally 

considered to have a low toxicity profile 

when used appropriately and within 

established dosing ranges (see DCN 

70081). Oil-based PAM and cationic 

PAM are known to exhibit acute and 

chronic aquatic toxicity. The Auckland, 

New Zealand Regional Council 

evaluated the ecotoxicological and 

environmental risk of polyelectrolytes 

and inorganic aluminum salts (see DCN 

70082) and found that ‘‘there appears to 

be a small risk to the natural aquatic 

environment arising from potential 

losses of unbound residual flocculants 

from treatment ponds on construction 

sites. Impacts are likely to be low level 

and also likely to not be significant in 

relation to other factors which govern 

the health of aquatic communities. The 

benefit of reduced sediment levels in 

discharges is considered to outweigh the 

risk of any low level impacts 

attributable to residual flocculants.’’ 

There are also concerns related to 

flocculated material containing 

polymers or other treatment chemicals 

that may pass through passive or semipassive treatment systems. Anecdotal 

information indicates that PAM bound 

to soil particles may be discharged to 

receiving waters in certain cases in 

simple passive treatment systems, either 

due to the flocculated material not being 

removed by the practice or previouslyremoved material being re-suspended 

during subsequent storm events. It is 

unclear what, if any, downstream effects 

may be attributable to these discharges, 

as sediment-bound PAM is thought to 

have limited bioavailability (see DCN 

70081). It is also unclear how any 

detrimental effects due to discharged 

chemical would compare to the 

detrimental effects of the additional 

sediment and turbidity that would be 

discharged had the chemical not been 

used. Additional concerns have been 

raised regarding the disposal of 

treatment residuals, which consist of 

sediment bound with treatment 

chemicals. Common practice is to use 

treatment residuals as fill material. If fill 

material is placed in locations that are 

not adjacent to surface waters and in 

areas where they cannot be remobilized, then the potential for 

subsequent release may be minimized. 

However, EPA is not aware of data or 

studies that have looked at the fate and 

transport of treatment chemicals 

contained in residuals. It is, however, 

generally known that components of 

some chemicals, such as 

polysaccharides, will readily degrade 

into benign compounds. And, as stated 

in the previous paragraph, sedimentbound PAM is thought to have limited 

bioavailability since there is little or no 

desorption from soil particles. 

EPA is seeking comment and 

additional data on the toxicity 

associated with the use of chemicals in 

controlling sediment discharge in 

construction stormwater. 

F. Cold Weather Considerations 

EPA solicits information and data on 

the performance of polymers as an aid 

to reducing turbidity in cold weather. 

EPA is aware that temperature may 

affect dissolution rates of treatment 

chemicals and therefore may impact the 

performance of polymer-aided settling 

and filtration (see DCN 70000, 70001 

and 70002). Data contained in DCN 

70000 indicates that while dissolution 

rates may be lower, there are methods 

available to mitigate detrimental effects 

on treatment system performance, such 

as providing additional application in 

order to provide the proper dosing rates 

and/or use of product formulations 

designed specifically for use in colder 

climates. Directing discharges to a 

vegetated buffer (or biofilter) would also 

be expected to provide additional 

removal (see DCN 70000, which 

illustrates such an application in a cold 

climate). This issue was addressed in 

EPA’s comment response document for 

the December 2009 final rule (EPA–HQ– 

OW–2008–0465–1660, page 507): 


pmangrum on DSK3VPTVN1PROD with NOTICES
122 Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 

EPA expects that NPDES permittees 

working in cold-climate regions, such as 

Alaska, shall be able to comply with the 

requirements of the final rule. Very little 

surface runoff (and hence discharges) occurs 

during freezing conditions. As temperatures 

warm and snow and ice melt and discharges 

occur, the limitation would apply to 

discharges on those sites that meet the 

applicability criteria. In some cases, 

permittees may need to consider the need for 

freeze protection for items such as pumps 

and polymer dosing systems, if permittees 

elect to use these or other items as 

components of their treatment systems. 

Stormwater infiltration may be limited in 

cold climates, but the ELGs are flexible 

enough to allow permittees to comply with 

the regulation regardless of frozen soil/ 

ground conditions. 

In addition, comments submitted by 

the National Association of Home 

Builders on the November 29, 2008 

proposed rule (EPA–HQ–OW–2008– 

0465–1360.2, page 188) indicate that 

little, if any, runoff would be expected 

during the cold months: 

In very cold climates, erosion and 

sediment movement is nonexistent during 

the cold months. Once the freeze sets in, the 

soil does not move since the freeze penetrates 

to well below the surface. Typically builders 

and contractors do their land disturbing 

activities during the summer months. (Home 

builders line up a number of home 

foundations where the building of the houses 

can proceed during the winter without the 

need to move soil.) If digging is done on site 

during the winter to put in a foundation, the 

soil removed will remain in place until the 

thaw. Permitting authorities normally require 

that sites are stabilized prior to freezing and 

inspections take place to ensure stabilization 

during the spring, including stabilization for 

any dirt dug out during the winter. 

EPA solicits additional data on the 

performance of polymer-aided settling 

and filtration in colder climates. 

G. Small Sites That Are Part of a Larger 

Common Plan of Development or Sale 

EPA solicits comments on the ability 

to effectively treat discharges from small 

sites that are part of a larger common 

plan of development or sale. An 

example would be a site that is above 

any regulatory threshold requiring 

compliance with a turbidity limitation, 

but has a portion of the site (such as an 

individual lot or small group of lots) 

that may not be treated in a common 

system that treats discharges for the 

entire site. These small areas would still 

be subject to any numeric limitation 

because the overall size of the 

construction site exceeds the size 

threshold, and therefore these sites 

would need to treat any discharge from 

their area if there is a concentrated point 

of discharge that would be subject to the 

numeric limitation. EPA is soliciting 

data and information on the ability to 

apply treatment to small areas within a 

larger common plan of development or 

sale. 

Information in the record for the C&D 

rule indicates polymer-aided settling 

and filtration is scalable, and that 

therefore there are technologies 

available that can be used on any size 

site and any drainage area. Some of the 

data used to calculate the December 

2009 numeric limitation, such as the 

North Carolina roadway project and the 

North Carolina institutional project, 

were collected on small drainage areas. 

Small drainage areas need only provide 

a sufficient storage volume (such as a 

sediment trap) or a conveyance system 

(such as a channel with check dams) to 

treat stormwater discharges. 

For small drainage areas without 

appreciable slope, or where a 

conveyance or impoundment could not 

be feasibly installed, EPA would expect 

that stormwater would be conveyed 

primarily as overland flow, once the 

underlying soil has been saturated, 

which would be amenable to treatment 

through a filter berm, vegetated buffer or 

other appropriate control. EPA would 

not expect stormwater discharges to 

become concentrated to such a degree 

from small, flat drainage areas that 

monitoring and compliance with a 

numeric limitation would be required 

since channelization is likely not to 

occur, except for larger storm events. In 

addition, the use of surface covers, 

tackifiers and other covers have been 

shown to be highly effective in 

preventing mobilization of soil particles 

(see the Technical Development 

Document for the December 2009 rule 

for additional information). These 

practices can be used on any size area 

of disturbance and would be 

particularly effective on small, flat areas 

of disturbance. Therefore, EPA believes 

that technologies are available for 

managing any size site or drainage area. 

EPA further believes that decisions 

the permittee chooses to make regarding 

how to grade the site and how to convey 

stormwater are important factors to 

consider during the planning phase of a 

project, and that these choices will 

affect the level of technology needed to 

meet a turbidity limitation and the 

number of discharge points that will 

require monitoring, particularly for 

smaller drainage areas. EPA solicits 

comment and data on this issue. 

H. Electric Utility Transmission Line 

Construction 

EPA solicits information and data on 

the costs and feasibility of 

implementing controls to achieve a 

numeric effluent limitation for turbidity 

in discharges from electric utility 

transmission line construction projects. 

As discussed below, the length of 

electric utility transmission line 

projects, the multitude of discharge 

points, the distance between such 

discharge points, and the relatively brief 

construction period would make it 

potentially difficult for permittees to 

identify all discharge points in advance 

and monitor at the numerous points 

where monitoring would potentially be 

required. 

Since promulgation of the December 

2009 C&D rule, EPA has received 

information from UWAG (see DCN 

70031) regarding several attributes of 

construction for electric utility 

transmission line construction projects. 

Information provided to the Agency and 

the Agency’s understanding of this 

information indicates that electric 

utility transmission line construction 

projects are different than other types of 

linear construction projects, such as 

roads. Electric utility transmission line 

construction projects can span 

anywhere from a few dozen miles to 

hundreds of miles in length and the area 

of disturbance is typically noncontiguous. Other linear construction 

projects, such as roads, typically do not 

span the longer distances in this range 

and typically have relatively contiguous 

areas of disturbance. EPA’s 

understanding of the information 

provided by UWAG indicates that, given 

the considerable length of electric 

transmission projects and the number of 

individual areas where pads and/or 

poles are installed, the number of 

discharge points could run into the 

hundreds. This number of discharge 

points is unique to long, linear electric 

utility transmission line construction 

projects. Further, the distance between 

individual areas of disturbance for 

electric utility transmission line 

construction projects can be 

considerable. This differs from other 

linear projects, such as roads, in that 

other linear projects typically do not 

have such distances between areas of 

disturbance. For example, a typical road 

widening project could potentially be 

up to dozens of miles long, but the areas 

of disturbance are generally contiguous 

or in close proximity to each other. 

Another significant difference 

between electric utility transmission 

line construction projects and other 

linear construction projects is that the 

duration of disturbance for a given piece 

of land is typically much shorter and 

the intensity of disturbance is much less 

for electric utility transmission line 

construction projects than for other 

linear construction projects, such as 

roads. Construction of a new roadway, 


pmangrum on DSK3VPTVN1PROD with NOTICES
Federal Register / Vol. 77, No. 1 / Tuesday, January 3, 2012 / Notices 123 

or expansion of an existing roadway to 

add a new lane or lanes, typically takes 

many months and involves intensive 

land disturbance (clearing, grading, cut 

and fill, excavation, etc.), whereas 

construction of an individual pad for an 

electric utility transmission line tower 

and/or pole may last a matter of days or 

weeks. 

Based on the length of such electric 

utility transmission line construction 

projects, the multitude of discharge 

points, the distance between such 

discharge points, and the relatively brief 

construction period, EPA solicits 

comments on whether it would be 

practical to require such dischargers to 

identify all discharge points in the 

notice of intent to be covered for their 

permit, for the permitting authority to 

determine representative discharge 

points, and for the discharger to monitor 

at the numerous points where 

monitoring would potentially be 

required for these types of projects. EPA 

solicits comments on the information 

provided to EPA by UWAG and 

additional data on construction of 

electric utility transmission lines to 

support or refute the ability of these 

projects to implement controls and 

monitor discharges. 

Dated: December 27, 2011. 

Michael H. Shapiro, 

Acting Assistant Administrator for Water. 

[FR Doc. 2011–33661 Filed 12–30–11; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

[FRL–9615–1] 

Final Reissuance of General NPDES 

Permits (GP) for Facilities Related to 

Oil and Gas Extraction 

AGENCY: Environmental Protection 

Agency, Region 10. 

ACTION: Final Notice of reissuance of a 

general permit. 

SUMMARY: A GP regulating the activities 

of facilities related to oil and gas 

extraction on the North Slope of the 

Brooks Range, Alaska expired on 

January 2, 2009. On July 2, 2009, EPA 

proposed to reissue the GP expanding 

the coverage area to the TransAlaska 

Pipeline Corridor along with other 

potential corridors. There was a 45 day 

comment period. During the comment 

period, EPA received many comments 

and decided to make changes to the 

draft based on the comments received. 

On August 2, 2011, EPA re-noticed the 

GP with a new Fact Sheet requesting 

new comments. The comment permit 

ended on September 17, 2011. 

EPA received several comments, the 

major one being a request not to cover 

the pipeline corridors under this GP. 

EPA agreed so the final coverage area 

reverts back to the North Slope Borough, 

Alaska. EPA has also renumbered the 

permit to distinguish it from the 

previous GP which covered more types 

of discharges. 

DATES: The GP (Permit Number AKG– 

33–1000 formerly AKG–33–0000) will 

be effective February 2, 2012. Facilities 

with administratively extended 

coverage under the expired GP whose 

discharges are covered by the GP will be 

covered on the effective date of this GP 

thus ending any administrative 

extension for those permittees. Facilities 

that are not covered by the new GP but 

have administratively extended 

coverage under the previous GP will 

continue to have coverage under AKG– 

33–0000 until a new permit is issued to 

address those discharges. 

ADDRESSES: Copies of the GP and 

Response to Comments are available 

upon request. Written requests may be 

submitted to EPA, Region 10, 1200 Sixth 

Avenue, Suite 900, OWW–130, Seattle, 

WA 98101. Electronic requests may be 

mailed to: washington.audrey@epa.gov 

or godsey.cindi@epa.gov 

FOR FURTHER INFORMATION CONTACT: The 

GP, Fact Sheet and Response to 

Comments may be found on the Region 

10 Web site at http://yosemite.epa.gov/ 

r10/water.nsf/NPDES+Permits/ 

General+NPDES+Permits. Requests by 

telephone may be made to Audrey 

Washington at (206) 553–0523 or to 

Cindi Godsey at (907) 271–6561. 

SUPPLEMENTARY INFORMATION: 

Executive Order 12866: The Office of 

Management and Budget has exempted 

this action from the review 

requirements of Executive Order 12866 

pursuant to Section 6 of that order. 

The state of Alaska, Department of 

Environmental Conservation (ADEC), 

certified on December 19, 2011, that the 

subject discharges comply with the 

applicable provisions of Sections 208(e), 

301, 302, 306 and 307 of the Clean 

Water Act. 

Regulatory Flexibility Act: Under the 

Regulatory Flexibility Act (RFA), 5 

U.S.C. 601 et seq., a Federal agency 

must prepare an initial regulatory 

flexibility analysis ‘‘for any proposed 

rule’’ for which the agency ‘‘is required 

by section 553 of the Administrative 

Procedure Act (APA), or any other law, 

to publish general notice of proposed 

rulemaking.’’ The RFA exempts from 

this requirement any rule that the 

issuing agency certifies ‘‘will not, if 

promulgated, have a significant 

economic impact on a substantial 

number of small entities.’’ EPA has 

concluded that NPDES general permits 

are permits, not rulemakings, under the 

APA and thus not subject to APA 

rulemaking requirements or the RFA. 

Notwithstanding that general permits 

are not subject to the RFA, EPA has 

determined that these general permits, 

as issued, will not have a significant 

economic impact on a substantial 

number of small entities. 

Dated: December 22, 2011. 

Michael A. Bussell, 

Director, Office of Water & Watersheds, 

Region 10, U.S. Environmental Protection 

Agency. 

[FR Doc. 2011–33663 Filed 12–30–11; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

[FRL–9615–2] 

Proposed CERCLA Administrative 

Cost Recovery Settlement; North 

Hollywood Operable Unit of the San 

Fernando Valley Area 1 Superfund Site 

AGENCY: Environmental Protection 

Agency. 

ACTION: Notice; request for public 

comment. 

SUMMARY: In accordance with Section 

122(i) of the Comprehensive 

Environmental Response, 

Compensation, and Liability Act, as 

amended (‘‘CERCLA’’), 42 U.S.C. 

9622(i), notice is hereby given of a 

proposed administrative settlement for 

recovery of response costs concerning 

the North Hollywood Operable Unit of 

the San Fernando Valley Area 1 

Superfund Site, located in the vicinity 

of Los Angeles, California, with the 

following settling party: Waste 

Management Recycling & Disposal 

Services of California, Inc., dba Bradley 

Landfill & Recycling Center. The 

settlement requires the settling party to 

pay a total of $185,734 to the North 

Hollywood Operable Unit Special 

Account within the Hazardous 

Substance Superfund. The settlement 

also includes a covenant not to sue the 

settling party pursuant to Section 107(a) 

of CERCLA, 42 U.S.C. 9607(a). For thirty 

(30) days following the date of 

publication of this notice, the Agency 

will receive written comments relating 

to the settlement. The Agency will 

consider all comments received and 

may modify or withdraw its consent to 

the settlement if comments received 

disclose facts or considerations which 


pmangrum on DSK3VPTVN1PROD with NOTICES