[Federal Register: December 1, 2009 (Volume 74, Number 229)]
[Rules and Regulations]
[Page 62995-63058]
[DOCID:fr01de09-22]

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Part III

Environmental Protection Agency

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40 CFR Part 450

Effluent Limitations Guidelines and Standards for the Construction and
Development Point Source Category; Final Rule

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 450

[EPA-HQ-OW-2008-0465; FRL-9086-4]
RIN 2040-AE91

Effluent Limitations Guidelines and Standards for the
Construction and Development Point Source Category

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency is publishing final
regulations establishing Clean Water Act (CWA) technology-based
Effluent Limitations Guidelines and New Source Performance Standards
for the Construction and Development (C&D) point source category. EPA
expects compliance with this regulation to reduce the amount of
sediment and other pollutants discharged from construction and
development sites by approximately 4 billion pounds per year.

DATES: This final rule is effective on February 1, 2010, 60 days after
publication in the Federal Register.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OW-2008-0465. All documents in the docket are listed on the
http://www.regulations.gov Web site. 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, is not placed on the Internet and will be
publicly available only in hard copy form. Publicly available docket
materials are available either electronically through http://
www.regulations.gov or in hard copy at the Office of 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<PHONE_NUMBER>, and the telephone number for the
Office of Water Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: For technical information concerning
today's rule, contact Mr. Jesse W. Pritts at<PHONE_NUMBER>
(pritts.jesse@epa.gov). For economic information contact Mr. Todd Doley
at<PHONE_NUMBER> (doley.todd@epa.gov). For information regarding
environmental benefits, contact Ms. Ashley Allen at<PHONE_NUMBER>
(allen.ashley@epa.gov).

SUPPLEMENTARY INFORMATION:

Regulated Entities

    Entities potentially regulated by this action include:

----------------------------------------------------------------------------------------------------------------
                                                                                North American
                                                                                industry
                   Category                            Examples of regulated entities            classification
                                                                                system (NAICS)
                                                                                code
----------------------------------------------------------------------------------------------------------------
Industry.....................................  Construction activities required to obtain
                                                NPDES permit coverage and performing the
                                                following activities:
                                               Construction of buildings, including building,                236
                                                developing and general contracting.
                                               Heavy and civil engineering construction,                     237
                                                including land subdivision.
----------------------------------------------------------------------------------------------------------------

    EPA does not intend the preceding table to be exhaustive, but
provides it as a guide for readers regarding entities likely to be
regulated by this action. This table lists the types of entities that
EPA is now aware could potentially be regulated by this action. Other
types of entities not listed in the table could also be regulated. To
determine whether your facility is regulated by this action, you should
carefully examine the applicability criteria in Sec.  450.10 of today's
final rule 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 site,
consult one of the persons listed for technical information in the
preceding FOR FURTHER INFORMATION CONTACT section.

Supporting Documentation

    Several key documents support the final regulation:
    1. ``Development Document for Final Effluent Guidelines and
Standards for the Construction and Development Category,'' EPA-821-R-
09-010. (``Development Document'') This document presents EPA's
methodology and technical conclusions concerning the C&D category.
    2. ``Economic Analysis for Final Effluent Guidelines and Standards
for the Construction and Development Category,'' EPA-821-R-09-011.
(``Economic Analysis'') This document presents the methodology employed
to assess economic impacts of the rule and the results of the analysis.
    3. ``Environmental Impact and Benefits Assessment for Final
Effluent Guidelines and Standards for the Construction and Development
Category,'' EPA-821-R-09-012 (``Environmental Assessment''). This
document presents the methodology to assess environmental impacts and
benefits of the rule and the results of the analysis.
    You can obtain electronic copies of this preamble and final rule as
well as the technical and economic support documents for today's rule
at EPA's Web site for the C&D rule, http://www.epa.gov/waterscience/
guide/construction.

Overview

    This preamble describes the terms, acronyms, and abbreviations used
in this document; the background documents that support these final
regulations; the legal authority of this final rule; a summary of the
final rule; background information; and the technical and economic
methodologies used by the Agency to develop this final regulation.

Table of Contents

I. Legal Authority
II. Purpose & Summary of the Final Rule
III. Background on Existing Regulatory Program
    A. Clean Water Act
    B. Clean Water Act Stormwater Program
    1. NPDES Permits for Stormwater Discharges Associated With
Construction Activity
    a. General NPDES Permits
    b. EPA Construction General Permit
    c. State Construction General Permits
    d. Individual NPDES Permits
    2. Municipal Stormwater Permits and Local Government Regulation
of Stormwater Discharges Associated With Construction Activity
    a. NPDES Requirements
    b. EPA Guidance to Municipalities
    C. Other State and Local Stormwater Requirements
    D. Technology-Based Effluent Limitations Guidelines and
Standards
    1. Best Practicable Control Technology Currently Available (BPT)

    2. Best Available Technology Economically Achievable (BAT)
    3. Best Conventional Pollutant Control Technology (BCT)
    4. Best Available Demonstrated Control Technology (BADT) for New
Source Performance Standards (NSPS)
    5. Pretreatment Standards
    6. EPA Authority to Promulgate Non-Numeric Effluent Limitations
    7. CWA Section 304(m) Litigation
IV. Overview of the Construction Industry and Construction
Activities
V. Summary of the Proposed Regulation
VI. Summary of Major Comments Received
VII. Summary of Significant Decisions and Revisions to Analyses
    A. Regulatory Options
    B. Cost Analysis
    C. Pollutant Load Analysis
    D. Economic Analysis
    E. Benefits Estimation and Monetization
VIII. Characteristics of Discharges Associated With Construction
Activity
IX. Description of Available Technologies
    A. Introduction
    B. Erosion Control Measures
    C. Sediment Control Measures
    D. Other Construction and Development Site Management Practices
    E. Performance Data for Passive Treatment Approaches
X. Development of Effluent Limitations Guidelines and Standards and
Options Selection Rationale
    A. Description of the Regulatory Options Considered
    1. Options Considered in the Proposal
    2. Regulatory Options Considered for the Final Rule and
Rationale for Consideration of Revisions to Options in the Proposed
Rule
    B. Non-Numeric Effluent Limitations Included in All Regulatory
Options
    1. Non-Numeric Effluent Limitations Contained in the Final Rule
    2. Changes to the Non-Numeric Effluent Limitations Since
Proposal
    C. Numeric Effluent Limitations and Standards Considered
    D. Selected Options for BPT, BCT, BAT and BADT for NSPS
    E. Selection Rationale for BPT
    F. Selection Rationale for BCT
    G. Selection Rationale for BAT and BADT for NSPS
    1. Selection Rationale
    2. Numeric Limitations
    3. Rationale for Rejecting Options 1, 2 and 3 as the Technology-
Bases for BAT and BADT for NSPS
    4. Definition of ``New Source'' for the C&D Point Source
Category
XI. Methodology for Estimating Costs to the Construction and
Development Industry
XII. Economic Impact and Social Cost Analysis
    A. Introduction
    B. Description of Economic Activity
    C. Method for Estimating Economic Impacts
    1. Model Project Analysis
    2. Model Firm Analysis
    a. Assigning Projects and Costs to Model Firms
    b. Project-Level Cost Multiplier
    c. Cost Pass-through
    3. Housing Market Impacts
    4. Impacts on the National Economy
    D. Results
    1. Project-Level Impacts
    2. Firm-Level Impacts
    3. Impacts on Governments
    4. Community-Level Impacts
    5. Foreign Trade Impacts
    6. Impacts on New Firms
    7. Social Costs
    8. Small Business Impacts
XIII. Cost-Effectiveness Analysis
XIV. Non-Water Quality Environmental Impacts
    A. Air Pollution
    B. Solid Waste Generation
    C. Energy Usage
XV. Environmental Assessment
    A. Surface Water Impacts From Discharges Associated With
Construction Activity
    B. Quantification of Sediment Discharges Associated With
Construction Activity
    C. Quantification of Surface Water Quality Improvement From
Reducing Discharges Associated With Construction and Development
Activity
XVI. Benefit Analysis
    A. Benefits Categories Estimated
    B. Quantification of Benefits
XVII. Benefit-Cost Comparison
XVIII. Approach to Determining Effluent Limitations and Standards
    A. Definitions
    B. Percentile Basis for Limitations, not Compliance
XIX. Regulatory Implementation
    A. Monitoring Requirements
    B. Implementation
    C. Upset and Bypass Provisions
    D. Variances and Waivers
    E. Safe Drinking Water Act Requirements
    F. Other Clean Water Act Requirements
XX. Related Acts of Congress, Executive Orders, and Agency
Initiatives
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175 (Consultation and Coordination With
Indian Tribal Governments)
    G. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    H. Executive Order 13211 (Energy Effects)
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations.
    K. Congressional Review Act (CRA)
    L. Judicial Review

I. Legal Authority

    EPA is promulgating these regulations under the authorities of
sections 101, 301, 304, 306, 308, 402, 501 and 510 of the Clean Water
Act (CWA), 33 U.S.C. 1251, 1311, 1314, 1316, 1318, 1341, 1342, 1361 and
1370 and pursuant to the Pollution Prevention Act of 1990, 42 U.S.C.
13101 et seq.

II. Purpose & Summary of the Final Rule

    EPA is today promulgating effluent limitations guidelines (ELG) and
new source performance standards (NSPS) for the C&D point source
category. EPA is promulgating a series of non-numeric effluent
limitations, as well as a numeric effluent limitation for the pollutant
turbidity. All construction sites will be required to meet the series
of non-numeric effluent limitations. Construction sites that disturb 10
or more acres of land at one time will be required to monitor
discharges from the site and comply with the numeric effluent
limitation. EPA is phasing in the numeric effluent limitation over four
years to allow permitting authorities adequate time to develop
monitoring requirements and to allow the regulated community time to
prepare for compliance with the numeric effluent limitation.
Construction sites that disturb 20 or more acres at one time will be
required to conduct monitoring of discharges from the site and comply
with the numeric effluent limitation beginning 18 months after the
effective date of the final rule. Construction sites that disturb 10 or
more acres at one time will be required to conduct monitoring of
discharges from the site and comply with the numeric effluent
limitation beginning four years after the effective date of the final
rule.
    The total pollutant reductions, once fully implemented, will be
approximately 4 billion pounds per year. The final rule will result in
an extensive range of benefits. For some of those benefits EPA was able
to estimate a monetized value of approximately $369 million per year,
once fully implemented. EPA could not monetize the value of some
benefit categories, such as increases in property value near water
bodies, reduced flood damage, and reduced cost of ditch maintenance.
For other benefits categories, such as swimming and fishing, EPA was
able to partially monetize the benefits. The costs of the final rule in
2010, which is the first year in which the rule must be incorporated
into National Pollutant Discharge Elimination System (NPDES) permits,
are estimated to be $8 million. Costs in 2011 are estimated to be $63
million. Since this regulation will be implemented over time due to the
schedule by which EPA and states will be issuing new or reissued
permits, the annual cost of the rule will be $810 million after all
states have incorporated the requirements of the final rule into their
NPDES permits in 2014. EPA

expects that after the rule is fully incorporated into EPA and state
NPDES permits after the industry has returned to normal levels of
construction activity, the annual cost of the rule will be $953
million.
    The goal of the Clean Water Act is to restore and maintain the
chemical, physical and biological integrity of the Nation's waters. CWA
section 101, 33 U.S.C. 1251. Despite substantial improvements in the
nation's water quality since the inception of the Clean Water Act, many
of the nation's surface waters continue to be impaired. EPA's
Assessment TMDL Tracking and Implementation System (ATTAINS) provides
information on water quality conditions reported by the states to EPA
under Sections 305(b) and 303(d) of the Clean Water Act. According to
ATTAINS (as of September 17, 2009), 49 percent of assessed river and
stream miles, 66 percent of assessed lake area, and 63 percent of
assessed bay and estuary area is impaired by a wide range of sources.
Improper control of stormwater discharges associated with construction
activity is a contributor of sediment, turbidity, nutrients and other
pollutants to surface waters in the United States. Sediment (both
suspended and deposited) and turbidity are common construction site
pollutants and are significant causes of surface water quality
impairment. According to ATTAINS (as of September 17, 2009), turbidity
contributes to impairment of 26,278 miles of assessed rivers and
streams, 1,008,276 acres of assessed lakes, and reservoirs, and 240
square miles of assessed bays and estuaries. These figures probably
underestimate the extent of turbidity impairment since many waters have
not yet been assessed. EPA's Wadeable Streams Assessment (2006) is a
statistical survey of the smaller perennial streams and rivers that
comprise 90 percent of all perennial stream miles in the coterminous
United States. According to the survey, excess streambed sedimentation
is one of the most widespread stressors, with 25 percent of streams in
``poor'' streambed sediment condition.
    The sediment, turbidity, and other pollutants entrained in
stormwater discharges associated with construction activity contribute
to aquatic ecosystem degradation, increased drinking water treatment
costs, and impairment of the recreational use and aesthetic value of
impacted waters. Sediment can also accumulate in rivers, lakes, and
reservoirs, leading to the need for dredging or other mitigation in
order to prevent reduced water storage or navigation capacity.
    Construction activity typically involves site selection and
planning, and land-disturbing tasks such as clearing, excavating and
grading. Disturbed soil, if not managed properly, can be easily washed
off-site during storm events. Stormwater discharges during construction
activities containing sediment and turbidity can cause an array of
physical, chemical and biological impacts on receiving waters. In
addition to sediment and turbidity, a number of other pollutants (e.g.,
metals, organic compounds and nutrients) are preferentially absorbed or
adsorbed onto mineral or organic particles found in fine sediment.
These pollutants can cause an array of chemical and biological water
quality impairments. The interconnected processes of erosion (i.e.,
detachment of soil particles by water), sediment transport, and
delivery to receiving waters are the primary pathways for the addition
of pollutants from construction and development sites (hereinafter C&D
sites; construction sites; or sites) into aquatic systems.
    A primary concern at most C&D sites is the erosion and transport
process related to fine sediment because rain splash, rills (small
channels typically less than one foot deep) and sheetwash (thin sheets
of water flowing across a surface) encourage the detachment and
transport of sediment to water bodies. Although streams and rivers
naturally carry sediment loads, discharges associated with construction
activity can elevate these loads to levels above those in undisturbed
watersheds. In addition, discharges from C&D sites can increase the
proportion of silt, clay and colloidal particles in receiving streams
because these fine-grained particles may not be effectively managed by
conventional erosion and sediment controls utilized at C&D sites that
rely on simple settling.
    Existing national stormwater regulations at 40 CFR 122.26 require
dischargers engaged in construction activity to obtain NPDES permit
coverage and to implement control measures to manage discharges
associated with construction activity. This category is the largest
category of dischargers in the NPDES program. However, there are
currently no national performance standards or monitoring requirements
for this category of dischargers. Today's regulation establishes a
technology-based ``floor'' or minimum requirements on a national basis.
This rule constitutes the nationally applicable, technology-based ELG
and NSPS applicable to all dischargers currently required to obtain a
NPDES permit pursuant to 40 CFR 122.26(b)(14)(x) and 122.26(b)(15).
This rule focuses on discharges composed of stormwater but the ELGs and
NSPSs also apply to other discharges of pollutants from C&D sites, such
as discharges from dewatering activities. CWA section 301(a). The ELGs
and NSPSs would require stormwater discharges from most C&D sites to
meet effluent limitations designed to reduce the amount of sediment,
turbidity, Total Suspended Solids (TSS) and other pollutants in
stormwater discharges from the site.
    EPA acknowledges that many state and local governments have
existing programs for controlling stormwater and wastewater discharges
from construction sites. Today's ELGs and NSPS are intended to work in
concert with these existing state and local programs and in no way does
EPA intend for this regulation to interfere with existing state and
local requirements that are more stringent than this rule or with the
ability of state and local governments to promulgate new and more
stringent requirements. Today's regulation requires all permittees to
implement a range of erosion and sediment controls and pollution
prevention measures at regulated construction sites. Today's regulation
also establishes a numeric effluent limitation for turbidity in
discharges from C&D sites that disturb ten or more acres of land at one
time. Permittees would be required to sample stormwater discharges from
the site and report the levels of turbidity present in the discharges
to the permitting authority. These effluent limitations would, for many
sites, require an additional layer of management practices and/or
treatment above what most state and local programs are currently
requiring. Permitting authorities are required to incorporate these
turbidity limitations into their permits and permittees are required to
implement control measures to meet a numeric turbidity limitation in
discharges of stormwater from their C&D sites. EPA is not dictating
that specific technologies be used to meet the numeric limitation, but
is specifying the maximum daily turbidity level that can be present in
discharges from C&D sites. EPA's limitations are based on its
assessment of what specific technologies can reliably achieve.
Permittees have the flexibility to select management practices or
technologies that are best suited to site-specific conditions present
on each individual C&D site if they are able to consistently meet the
limitations and if they are consistent with requirements established by
the permitting authority.

Permittees also have the ability to phase their construction activities
to limit applicability of the monitoring requirements and turbidity
limitation.
    EPA expects that today's regulation will result in reductions in
pollutant discharges and substantial improvements in receiving water
quality nationally in areas where construction activities are occurring
and downstream of areas where construction activities are occurring. In
addition, the monitoring requirements contained in today's rule will
significantly increase transparency and accountability for the largest
category of NPDES dischargers and provide permittees, permitting
authorities and the public with an important mechanism for gauging
compliance with the regulations and standards.

III. Background on Existing Regulatory Program

A. Clean Water Act

    Congress passed the Federal Water Pollution Control Act of 1972
(Pub. L. 92-500, October 18, 1972) (hereinafter the Clean Water Act or
CWA), 33 U.S.C. 1251 et seq., with the stated objectives to ``restore
and maintain the chemical, physical, and biological integrity of the
Nation's waters.'' Section 101(a), 33 U.S.C. 1251(a). To achieve this
goal, the CWA provides that ``the discharge of any pollutant by any
person shall be unlawful'' except in compliance with other provisions
of the statute. CWA section 301(a). 33 U.S.C. 1311. The CWA defines
``discharge of a pollutant'' broadly to include ``any addition of any
pollutant to navigable waters from any point source.'' CWA section
502(12). 33 U.S.C. 1362(12). EPA is authorized under CWA section 402(a)
to issue a NPDES permit for the discharge of any pollutant from a point
source. These NPDES permits are issued by EPA regional offices or NPDES
authorized state or tribal agencies. Since 1972, EPA and the states
have issued NPDES permits to thousands of dischargers, both industrial
(e.g., manufacturing, energy and mining facilities) and municipal
(e.g., sewage treatment plants). As required under Title III of the
CWA, EPA has promulgated ELGs and standards for many industrial point
source categories, and these requirements are incorporated into the
permits. The Water Quality Act (WQA) of 1987 (Pub. L. 100-4, February
4, 1987) amended the CWA, adding CWA section 402(p), requiring
implementation of a comprehensive program for addressing stormwater
discharges. 33 U.S.C. 1342(p).

B. Clean Water Act Stormwater Program

    Prior to the WQA of 1987, there were numerous questions regarding
the appropriate means of regulating stormwater discharges within the
NPDES program due to the serious water quality impacts of stormwater,
the variable nature of stormwater, the large number of stormwater point
sources and permitting agency resources. EPA undertook numerous
regulatory actions, which resulted in extensive litigation, in an
attempt to address these unique discharges. Congress, with the addition
of section 402(p), established a structured and phased approach to
address stormwater discharges and fundamentally altered the way
stormwater is addressed under the CWA as compared with process
wastewater or other discharges of pollutants. Section 402(p)(1) created
a temporary moratorium on NPDES permits for point source stormwater
discharges, except for those listed in section 402(p)(2), including
dischargers already required to have a permit and discharges associated
with industrial activity. In 1990, pursuant to section 402(p)(4), EPA
promulgated the Phase I stormwater regulations for those stormwater
discharges listed in 402(p)(2). 55 FR 47990 (November 16, 1990). The
Phase I regulations required NPDES permit coverage for discharges
associated with industrial activity and from ``large'' and ``medium''
municipal separate storm sewer systems (MS4s). CWA section 402(p)(2).
As part of that rulemaking, the Agency interpreted stormwater
``discharges associated with industrial activity'' to include
stormwater discharges associated with ``construction activity'' as
defined at 40 CFR 122.26(b)(14)(x). As described in the Phase I
regulations, dischargers must apply for and obtain authorization to
discharge (or ``permit coverage''), and a permit is required for
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) and (c)(1). These discharges associated
with ``large'' construction activity are one of the categories of
stormwater dischargers EPA defined as associated with industrial
activity. See 40 CFR 122.26(b)(14).
    Section 402(p)(6) established a process for EPA to evaluate
potential sources of stormwater discharges not included in the Phase I
regulations and designation of those discharges for regulation in order
to protect water quality. Section 402(p)(6) instructs EPA to ``issue
regulations * * * which designate stormwater discharges, other than
those discharges described in [section 402(p)(2)], to be regulated to
protect water quality and shall establish a comprehensive program to
regulate such designated sources.'' In 1999, pursuant to the broad
discretion granted to the Agency under section 402(p)(6), EPA
promulgated the Phase II stormwater regulations which designated
discharges associated with ``small'' construction activity and
``small'' MS4s. 64 FR 68722 (December 8, 1999). An NPDES permit is
required for discharges associated with small construction activity,
including clearing, grading, and excavation, if the construction
activity:
     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).
    EPA continues to have the authority to use section 402(p)(6) to
designate additional stormwater discharges for regulation under the CWA
in order to protect water quality. See 40 CFR 122.26(a)(9)(i)(C)-(D);
see also Envt Defense Ctr. v. EPA, 344 F.3d 832, 873-76 (9th Cir.
2003).
    In addition, as stated above, the Phase I and Phase II regulations
require NPDES permits for ``large,'' ``medium,'' and ``small'' MS4s.
Operators of these MS4s, typically local governments, must develop and
implement a stormwater management program, including a requirement to
address stormwater discharges associated with construction activity and
discharges after construction activity. More details on the
requirements of MS4 programs are described in section III.B.2.
1. NPDES Permits for Stormwater Discharges Associated With Construction
Activity
    The NPDES regulations provide two options for obtaining
authorization to discharge or ``permit coverage'': General permits and
individual permits. A brief description of these types of permits as
they apply to C&D sites follows.

a. General NPDES Permits
    The vast majority of discharges associated with construction
activity are covered under NPDES general permits. EPA, states and
tribes use general permits to cover a group of similar dischargers
under one permit. See 40 CFR 122.28. General permits simplify the
process for dischargers to obtain authorization to discharge, provide
permit requirements for any discharger that files a notice of intent to
be covered, and reduce the administrative workload for NPDES permitting
authorities. General permits, including a fact sheet describing the
rationale for permit conditions, are issued by NPDES permitting
authorities after an opportunity for public review of the proposed
general permit. Typically, to obtain authorization to discharge under a
construction general permit, a discharger (the owner or operator of the
C&D sites; typically, a developer, builder, or contractor) submits to
the permitting authority a Notice of Intent (NOI) to be covered under
the general permit. A NOI is not a permit or a permit application, see
Texas Independent Producers and Royalty Owners Ass'n v. EPA, 410 F.3d
964, 977-78 (7th Cir. 2005), but by submitting the NOI, the discharger
acknowledges that it is eligible for coverage under the general permit
and agrees to the conditions in the published general permit.
Discharges associated with the construction activity are authorized
consistent with the terms and conditions established in the general
permit.
    EPA regulations allow NPDES permitting authorities to regulate
discharges from small C&D sites under a general permit without the
discharger submitting an NOI if the permitting authority determines an
NOI is inappropriate and the general permit includes language
acknowledging that an NOI is unnecessary (40 CFR 122.28(b)(2)(v)). To
implement such a requirement, the permitting authority must specify in
the public notice of the general permit any reasons why an NOI is not
required. In these instances, any stormwater discharges associated with
small construction activity are automatically covered under an
applicable general permit and the discharger is required to comply with
the terms, conditions and effluent limitations of such permit.
    Similarly, EPA, states and tribes have the authority to notify a
C&D site operator that it is covered by a general permit, even if that
operator has not submitted an NOI (40 CFR 122.28(b)(2)(vi)). In these
instances, the operator is given the opportunity to request coverage
under an individual permit. Individual permits are discussed in section
III.B.1.d.
b. EPA Construction General Permit
    Since 1992, EPA has issued a series of ``national'' Construction
General Permits (CGP) 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 a
couple of other specifically designated activities in specific states
(e.g., oil and gas activities in Texas and Oklahoma). EPA's current CGP
became effective on June 30, 2008 (see 74 FR 40338). EPA has proposed
to modify the expiration date of the current 2008 CGP for one year, to
June 30, 2011, in order to allow EPA adequate time to incorporate the
ELGs and NSPS in this final rule and provide any necessary guidance to
the regulated industry (see 74 FR 53494). At that time, EPA will issue
a new CGP that includes the requirements of this final rule.
    The key components of EPA's current CGP are non-numeric effluent
limitations and ``best management practices'' (BMP) that require the
permittee to minimize discharges of pollutants in stormwater discharges
using control measures that reflect best engineering practices based on
EPA's best professional judgment. Dischargers must minimize their
discharge of pollutants in stormwater using appropriate erosion and
sediment controls and control measures for other pollutants such as
litter, construction debris, and construction chemicals that could be
exposed to stormwater and other wastewater. The 2008 EPA CGP requires
dischargers to develop and implement a stormwater pollution prevention
plan (SWPPP) to document the steps they will take to comply with the
terms, conditions and effluent limitations of the permit. EPA's
guidance manual, ``Developing Your Stormwater Pollution Prevention
Plan: A Guide for Construction Sites,'' (EPA 833/R-060-04, May 2007;
available on EPA's Web site at http://www.epa.gov/npdes/stormwater)
describes the SWPPP process in detail. As detailed in EPA's CGP, the
SWPPP must include a description of the C&D site with maps showing
drainage patterns, discharge points, and locations of discharge
controls; a description of the control measures used; and inspection
procedures. A copy of the SWPPP must be kept on the construction site
from the date of project initiation to the date of final stabilization.
The CGP does not require permittees to submit a SWPPP to the permitting
authority; however, a copy must be readily available to authorized
inspectors during normal business hours. Other requirements in the CGP
include conducting regular inspections and reporting releases of
reportable quantities of hazardous substances.
c. State Construction General Permits
    Whether EPA, a state or a tribe issues the general permit, the CWA
and EPA regulations require that NPDES permits must include technology-
based effluent limitations. 40 CFR 122.44. In addition, where
technology-based effluent limitations are insufficient for the
discharge to meet applicable water quality standards, the permit must
contain water quality-based effluent limitations as necessary to meet
those standards. See sections 301, 304, 303, 306, and 402 of the CWA.
PUD No. 1 of Jefferson County v. Washington Department of Ecology, 511
U.S. 700, 704-705 (1994).
    For the most part, state-issued general permits for stormwater
discharges associated with construction activity have followed EPA's
CGP format and content, starting with EPA's first CGP issued in 1992
(57 FR 41176; September 9, 1992). Over time, some states have changed
components of their permits to better address the specific conditions
encountered at construction sites within their jurisdiction (e.g., soil
types, topographic or climatic characteristics, or other relevant
factors). For example, the States of Washington, Oregon, Georgia and
Vermont's CGPs include discharge monitoring requirements for C&D sites
applicable to all or a subset of construction sites. In addition, the
State of California's current CGP contains monitoring requirements as
well as numeric effluent limitations for a subset of construction sites
within the state.
d. Individual NPDES Permits
    A permitting authority may require any C&D site to apply for an
individual permit rather than using the general permit. Likewise, any
discharger may request to be covered under an individual permit rather
than seek coverage under an otherwise applicable general permit (40 CFR
122.28(b)(3)). Unlike a general permit, an individual permit is
intended to be issued to one permittee, or a few co-permittees.
Individual permits for stormwater discharges from construction sites
are

rarely used, but when done so, are most often used for very large
projects or projects located in sensitive watersheds. EPA estimates
that fewer than one half of one percent (< 0.5%) of all construction
sites are covered under individual permits.
2. Municipal Stormwater Permits and Local Government Regulation of
Stormwater Discharges Associated With Construction Activity
    Many local governments, as MS4 permittees, have a role to play in
the regulation of construction activities. This section provides an
overview of MS4 responsibilities associated with controlling stormwater
discharges associated with construction activity.
a. NPDES Requirements
    A municipal separate storm sewer system (MS4) is generally a
conveyance or system of conveyances owned or operated by a public body
that discharges to waters of the United States and is designed or used
for collecting or conveying stormwater. These systems are not combined
sewers and not part of a Publicly Owned Treatment Works (POTW). See 40
CFR 122.26(b)(8) for an exact definition. An MS4 is all large, medium,
and small municipal storm sewers or those designated as such under EPA
regulations. See 40 CFR 122.26(b)(18). The NPDES stormwater regulations
require many MS4s to apply for permits. In general, the 1990 Phase I
rule requires MS4s serving populations of 100,000 or more to obtain
coverage under an MS4 individual permit. See 40 CFR 122.26(a)(3). The
1999 Phase II rule requires most small MS4s located in urbanized areas
also to obtain coverage. See 40 CFR 122.33. Regardless of the type of
permit, MS4s are required to develop stormwater management programs
that detail the procedures they will use to control discharges of
pollutants in stormwater from the MS4.
    The Phase II regulations also provide permitting authorities or the
EPA Regional Administrator with the authority to designate any
additional stormwater discharges for permit coverage where he or she
determines that stormwater controls are needed for the discharge based
on wasteload allocations that are part of total maximum daily loads
(TMDL) that address pollutants of concern or that the discharge, or
category of discharges within a geographic area, contributes to a
violation of a water quality standard or is a significant contributor
of pollutants to waters of the United States. 40 CFR 122.26(9)(a)(i)(C)
and (D).
    Both the Phase I and II rules require regulated municipalities to
develop stormwater management programs which include, among other
elements, the control of discharges from construction sites. The Phase
I regulations require medium and large MS4s to implement and maintain a
program to reduce pollutants in stormwater discharges associated with
construction activities, including procedures for site planning,
requirements for structural and non-structural BMPs, procedures for
identifying priorities for inspecting sites and enforcing control
measures, and development and dissemination of appropriate educational
and training materials. In general, the Phase II regulations require
small MS4s to develop, implement, and enforce a program to control
pollutants in stormwater discharges associated with construction
activities which includes developing an ordinance to require
implementation of erosion and sediment control practices, to control
waste and to have procedures for site plan review and site inspections.
Thus, as described above, both the Phase I and Phase II regulations
specifically anticipate a local program for controlling stormwater
discharges associated with construction activity. See 40 CFR
122.26(d)(2)(iv)(D) for Phase I MS4s and 40 CFR 122.34(b)(4) for Phase
II MS4s. EPA has provided guidance materials to the NPDES permitting
authorities and MS4s that recommend components and activities for a
well-operated local stormwater management program.
    EPA promulgated two provisions intended to minimize potential
duplication of requirements or inconsistencies between requirements.
First, 40 CFR 122.35 provides that a small MS4 is allowed to rely on
another entity's program to satisfy its NPDES permit obligations,
including construction site control, provided the other entity
implements a program that is at least as stringent as the corresponding
NPDES permit requirements and the other entity agrees to implement the
control measures on the small MS4's behalf. Thus, for example, where a
county implements a construction site stormwater control program
already, and that program is at least as stringent as the controls
required by a small MS4's NPDES permit, the MS4 may reference that
program in the Notice of Intent to be covered by a general permit, or
in its permit application, rather than developing and implementing a
new program to require control of construction site stormwater within
its jurisdiction.
    Similarly, EPA or the state permitting authority may substitute
certain aspects of the requirements of the EPA or state permit by
incorporating by reference the requirements of a ``qualifying local
program'' in the EPA or state CGP. A ``qualifying local program'' is an
existing sediment and erosion control program that meets the minimum
requirements as established in 40 CFR 122.44(s). By incorporating a
qualifying local, state or tribal program into the EPA or state CGP,
construction sites covered by the qualifying program in that
jurisdiction would simply follow the incorporated local requirements in
order to meet the corresponding requirements of the EPA or state CGP.
b. EPA Guidance to Municipalities
    EPA developed several guidance documents for municipalities to
implement the NPDES Phase II rule.
     National Menu of BMPs (http://cfpub.epa.gov/npdes/
stormwater/menuofbmps/index.cfm). This document provides guidance to
regulated MS4s as to the types of practices they could use to develop
and implement their stormwater management programs. The menu includes
descriptions of practices that local programs can implement to reduce
impacts of stormwater discharges from construction activities.
     Measurable Goals Guidance for Phase II MS4s (http://
cfpub.epa.gov/npdes/stormwater/measurablegoals/index.cfm). This
document assists small MS4s in defining performance targets and
includes examples of goals for practices to control stormwater
discharges from construction activities.
     Stormwater Phase II Compliance Assistance Guide (EPA 833-
R-00-002, March 2000). The guide provides an overview of compliance
responsibilities for MS4s, small construction sites, and certain other
industrial stormwater discharges affected by the Phase II rule.
     Fact Sheets on various stormwater control technologies,
including hydrodynamic separators (EPA 832-F-99-017), infiltrative
practices (EPA 832-F-99-018 and EPA 832-F-99-019), modular treatment
systems (EPA 832-F-99-044), porous pavement (EPA 832-F-99-023), sand
filters (EPA 832-F-99-007), turf reinforcement mats (EPA 832-F-99-002),
vegetative covers (EPA 832-F-99-027), swales (EPA 832-F-99-006) and wet
detention ponds (EPA 832-F-99-048). (Available at http://www.epa.gov/
npdes/stormwater/; click on ``Publications.'')

C. Other State and Local Stormwater Requirements

    States and municipalities may have other requirements for flood
control, erosion and sediment control, and in

many cases, stormwater management. Many of these provisions were
enacted before the promulgation of the EPA Phase I stormwater rule
although many have been updated since. EPA found that all states have
laws for erosion and sediment control measures, with these laws
implemented by state, county, or local governments. A summary of
existing state requirements is provided in the Development Document.

D. Technology-Based Effluent Limitations Guidelines and Standards

    Effluent limitations guidelines and new source performance
standards are technology-based effluent limitations required by CWA
sections 301 and 306 for categories of point source discharges. These
effluent limitations, which can be either numeric or non-numeric, along
with water quality-based effluent limitations, if necessary, are
incorporated into NPDES permits. ELGs and NSPSs are based on the degree
of control that can be achieved using various levels of pollutant
control technology as defined in Title III of the CWA and outlined
below.
1. Best Practicable Control Technology Currently Available (BPT)
    In establishing effluent limitations guidelines for a point source
category, the CWA requires EPA to specify BPT effluent limitations for
conventional, toxic, and nonconventional pollutants. In doing so, EPA
is required to determine what level of control is technologically
available and economically practicable. CWA section 301(b)(1)(A). In
specifying BPT, the CWA requires EPA to look at a number of factors.
EPA considers the total cost of application of technology in relation
to the effluent reduction benefits to be achieved from such
application. The Agency also considers the age of the equipment and
facilities, the process employed and any required process changes,
engineering aspects of the application of the control technologies,
non-water quality environmental impacts (including energy
requirements), and such other factors as the Administrator deems
appropriate. CWA section 304(b)(1)(B). Traditionally, EPA establishes
BPT effluent limitations based on the average of the best performance
of facilities within the category of various ages, sizes, processes or
other common characteristics. Where existing performance is uniformly
inadequate, EPA may require higher levels of control than currently in
place in a category if the Agency determines that the technology can be
practicably applied. See e.g., American Frozen Foods Inst. v. Train,
539 F.2d 107, 117 (D.C. Cir. 1976).
    EPA assesses the cost-reasonableness of BPT limitations by
considering the cost of treatment technologies in relation to the
effluent reduction benefits achieved. This inquiry does not limit EPA's
broad discretion to adopt BPT limitations that are achievable with
available technology. This ``limited cost-benefit analysis'' is
intended to ``limit the application of technology only where the
additional degree of effluent reduction is wholly out of proportion to
the costs of achieving such marginal level of reduction.'' See EPA v.
National Crushed Stone Ass'n, 449 U.S. 64 71 (1980). Moreover, the
inquiry does not require the Agency to quantify benefits in monetary
terms. See, e.g., American Iron and Steel Institute v. EPA, 526 F.2d
1027, 1051 (3rd Cir. 1975).
    In balancing costs against the effluent reduction, EPA considers
the volume and nature of the expected discharges after application of
BPT and the cost and economic impacts of the required level of
pollution control. In past effluent limitation guidelines, BPT cost-
reasonableness comparisons ranged from $0.26 to $41.44 per pound
removed (in 2008 dollars). This range is not inclusive of all
categories regulated by BPT, but nonetheless represents a very broad
range of cost-reasonableness values. About half of the cost-
reasonableness values represented by this range are less than $2.99 per
pound (in 2008 dollars).
2. Best Available Technology Economically Achievable (BAT)
    BAT effluent guidelines are applicable to toxic (priority) and
nonconventional pollutants. EPA has identified 65 pollutants and
classes of pollutants as toxic pollutants, of which 126 specific
substances have been designated priority toxic pollutants. 40 CFR
401.15 and 40 CFR part 423, Appendix A. In general, BAT represents the
best available performance of facilities through application of the
best control measures and practices achievable including treatment
techniques, process and procedure innovations, operating methods, and
other alternatives within the point source category. CWA section
304(b)(2)(A). The factors EPA considers in assessing BAT include the
cost of achieving BAT effluent reductions, the age of equipment and
facilities involved, the processes employed, the engineering aspects of
the control technology, potential process changes, non-water quality
environmental impacts (including energy requirements), and such factors
as the Administrator deems appropriate. CWA section 304(b)(2)(B). The
Agency retains considerable discretion in assigning the weight to be
accorded to these factors. Weyerhaeuser Company v. Costle, 590 F.2d
1011, (D.C. Cir. 1978). An additional factor, derived from the
statutory phrase best available technology economically achievable, is
``economic achievability.'' CWA section 301(b)(2)(A). EPA may determine
the economic achievability of an option on the basis of the overall
effect of the rule on the industry's financial health. See E.I. du Pont
de Nemours & Co. v. Train, 430 U.S. 112, 129 (1977); American Frozen
Food Inst. v. Train, 539 F.2d 107, 131 (D.C. Cir. 1976). The Agency may
base BAT limitations upon effluent reductions attainable through
changes in a facility's processes and operations. See Texas Oil & Gas
Ass'n v. EPA, 161 F.3d 923, 928 (5th Cir. 1998) (citing ``process
changes'' as one factor EPA considers in determining BAT); see also,
American Meat Institute v. EPA, 526 F.2d 442, 464 (7th Cir. 1975). As
with BPT, where existing performance is uniformly inadequate, EPA may
base BAT upon technology transferred from a different subcategory or
from another category. See CPC International Inc. v. Train, 515 F.2d
1032, 1048 (8th Cir. 1975) (established criteria EPA must consider in
determining whether technology from one industry can be applied to
another); see also, Tanners' Council of America, Inc. v. Train, 540
F.2d 1188 (4th Cir. 1976). In addition, the Agency may base BAT upon
manufacturing process changes or internal controls, even when these
technologies are not common industry practice. See American Frozen
Foods Inst. v. Train, 539 F.2d 107, 132 (D.C. Cir. 1976); Reynolds
Metals Co. v. EPA, 760 F.2d 549, 562 (4th Cir. 1985); California &
Hawaiian Sugar Co. v. EPA, 553 F.2d 280 (2d Cir. 1977).
3. Best Conventional Pollutant Control Technology (BCT)
    The 1977 amendments to the CWA required EPA to identify effluent
reduction levels for conventional pollutants associated with BCT
technology for discharges from existing point sources. BCT is not an
additional limitation, but replaces Best Available Technology (BAT) for
control of conventional pollutants. In addition to other factors
specified in CWA section 304(b)(4)(B), the Act requires that EPA
establish BCT limitations after consideration of a two-part ``cost-
reasonableness'' test. EPA explained its methodology for the
development of BCT limitations in July 1986. 51 FR 24974 (July 9,
1986).

    Section 304(a)(4) designates the following as conventional
pollutants: biochemical oxygen demand (BOD5), total
suspended solids (TSS), fecal coliform, pH, and any additional
pollutants defined by the Administrator as conventional. 40 CFR 401.16.
The Administrator designated oil and grease as an additional
conventional pollutant. 44 FR 44501 (July 30, 1979).
4. Best Available Demonstrated Control Technology (BADT) for New Source
Performance Standards (NSPS)
    NSPS apply to all pollutants and reflect effluent reductions that
are achievable based on the BADT. New sources, as defined in CWA
section 306, have the opportunity to install the best and most
efficient production processes and wastewater treatment technologies.
As a result, NSPS should represent the greatest degree of effluent
reduction attainable through the application of the best available
demonstrated control technology. In establishing NSPS, CWA section 306
directs EPA to take into consideration similar factors that EPA
considers when establishing BAT, namely the cost of achieving the
effluent reduction and any non-water quality, environmental impacts and
energy requirements.
5. Pretreatment Standards
    The CWA also defines standards for indirect discharges, i.e.
discharges into publicly owned treatment works (POTWs). These standards
are known as Pretreatment Standards for Existing Sources (PSES) and
Pretreatment Standards for New Sources (PSNS), and are promulgated
under CWA section 307(b). EPA has no data concerning the discharge of
pollutants from construction sites to POTWs and POTW treatment plants.
Therefore, EPA did not propose PSES or PSNS for the C&D category and is
not promulgating PSES or PSNS for the C&D category. EPA determined that
the majority of construction sites discharge either directly to waters
of the U.S. or through MS4s. In some urban areas, construction sites
may discharge to combined sewer systems (i.e., sewers carrying both
stormwater and domestic sewage through a single pipe) which lead to
POTW treatment plants. Sediment and turbidity, which are the primary
pollutants associated with construction site discharges, are
susceptible to treatment in POTWs, using technologies commonly employed
such as primary clarification. EPA has no evidence that construction
site discharges to POTWs would cause interference, pollutant pass-
through or sludge contamination.
6. EPA Authority to Promulgate Non-Numeric Effluent Limitations
    The regulations promulgated today include non-numeric effluent
limitations that will control the discharge of pollutants from C&D
sites. It is well established that EPA has the authority to promulgate
non-numeric effluent limitations in addition to, or in lieu of, numeric
limitations. The CWA does not mandate the use of numeric limitations
and EPA's position finds support in the language of the CWA. The
definition of ``effluent limitation'' means ``any restriction * * * on
quantities, rates, and concentrations of chemical, physical,
biological, and other constituents * * *'' CWA section 502(11)
(emphasis added). EPA regulations reflect the Agency's long standing
interpretation that the CWA allows for non-numeric effluent
limitations. EPA regulations explicitly allow for non-numeric effluent
limitations for the control of toxic pollutants and hazardous
substances from ancillary industrial activities; for the control of
storm water discharges; when numeric effluent limitations are
infeasible; or when the practices are reasonably necessary to achieve
effluent limitations and standards or to carry out the purposes and
intent of the CWA. See 40 CFR 122.44(k).
    Federal courts have recognized EPA's authority under the CWA to use
non-numeric effluent limitations. In Citizens Coal Council v. U.S. EPA,
447 F3d 879, 895-96 (6th Cir. 2006), the Sixth Circuit, in upholding
EPA's use of non-numeric effluent limitations, agreed with EPA that it
derives authority under the CWA to incorporate non-numeric effluent
limitations for conventional and non-conventional pollutants. See also,
Waterkeeper Alliance, Inc. v. U.S. EPA, 399 F.3d 486, 496-97, 502 (2d
Cir. 2005) (EPA use of non-numerical effluent limitations in the form
of best management practices are effluent limitations under the CWA);
Natural Res. Def. Council, Inc. v. EPA, 673 F.2d 400, 403 (D.C. Cir.
1982) (``section 502(11) [of the CWA] defines `effluent limitation' as
`any restriction' on the amounts of pollutants discharged, not just a
numerical restriction.'').
7. CWA Section 304(m) Litigation
    EPA identified the C&D point source category in its CWA section
304(m) plan in 2000 as an industrial point source category for which
EPA intended to conduct rulemaking. 65 FR at 53008 and 53011 (August
31, 2000). On June 24, 2002, EPA published a proposed rule that
contained several options for the control of stormwater discharges from
construction sites, including ELGs and NSPSs. (67 FR 42644; June 24,
2002). On April 26, 2004, EPA chose to rely on the range of existing
programs, regulations, and initiatives that already existed at the
federal, state and local level and withdrew the proposed ELGs and
NSPSs. (69 FR 22472; April 26, 2004). On October 6, 2004, the Natural
Resources Defense Council, Waterkeeper Alliance and the states of New
York and Connecticut filed a complaint in federal district court
alleging that EPA's decision not to promulgate ELGs and NSPSs for the
C&D point source category violated a mandatory duty under the CWA. The
district court, in NRDC v. EPA, 437 F.Supp.2d 1137, 1139 (C.D. Cal.
2006), held that CWA section 304(m) imposes on EPA a mandatory duty to
promulgate ELGs and NSPSs for new industrial point source categories
named in a CWA section 304(m) plan. At that time EPA argued that the
district court should enter an order providing for a four-year schedule
for EPA to promulgate the ELGs and NSPSs in order to allow the Agency
the opportunity to collect additional data on the construction
industry, additional data on stormwater discharges associated with
construction activity, and to be able to have the time to solicit
additional data based on comments received on the proposed regulation.
The district court rejected EPA's proposed schedule, forcing the Agency
to proceed under an accelerated schedule by enjoining EPA in an order
to propose and publish ELGs and NSPSs for the C&D industry by December
1, 2008 and to promulgate and publish ELGs and NSPSs as soon as
practicable, but in no event later than December 1, 2009. See NRDC, et
al. v. EPA, No CV-0408307 (C.D. Cal.) (Permanent Injunction and
Judgment, December 5, 2006). On appeal, the Ninth Circuit in NRDC v.
EPA, 542 F.3d 1235 (9th Cir. 2008) affirmed the district court's
decision. Consistent with the district court order, EPA published
proposed ELGs and NSPSs on November 28, 2008 (see 73 FR 72562) and is
publishing final ELGs and NSPSs today.

IV. Overview of the Construction Industry and Construction Activities

    The C&D point source category covers firms classified by the Census
Bureau into two North American Industry Classification System (NAICS)
codes.
     Construction of Buildings (NAICS 236) includes
residential, nonresidential, industrial, commercial and institutional
building construction.
     Heavy and Civil Engineering Construction (NAICS 237)
includes utility systems construction (water and

sewer lines, oil and gas pipelines, power and communication lines);
land subdivision; highway, street, and bridge construction; and other
heavy and civil engineering construction.
    Other types of entities not included in this list could also be
regulated.
    A single construction project may involve many firms from both
subsectors. The number of firms involved and their financial and
operational relationships may vary greatly from project to project. In
typical construction projects, the firms identifying themselves as
``operators'' under a construction general permit are usually general
building contractors or developers. While the projects often engage the
services of specialty contractors such as excavation companies, these
specialty firms are typically subcontractors to the general building
contractor and are not separately identified as operators in stormwater
permits. Other classes of subcontractors such as carpentry, painting,
plumbing and electrical services typically do not apply for, nor
receive, NPDES permits. The types and numbers of firms in the
construction industry are described in more detail in the Economic
Analysis.
    Construction activity on any size parcel of land almost always
calls for a remodeling of the earth. Therefore, actual site
construction typically begins with site clearing and grading. Earthwork
activities are important in site preparation because they ensure that a
sufficient layer of organic material (ground cover and other
vegetation, especially roots) is removed. The size of the site, extent
of water present, the types of soils, topography and weather determine
the types of equipment that will be needed during site clearing and
grading. Material that will not be used on the site may be hauled away.
Clearing activities involve the movement of materials from one area of
the site to another or complete removal from the site. When grading a
site, builders typically take measures to ensure that new grades are as
close to the original grade as possible to reduce erosion and
stormwater runoff, which can result in discharge of sediment, turbidity
and other pollutants. Proper grade also ensures a flat surface for
development and is designed to attain proper drainage away from the
constructed buildings. A wide variety of equipment is often used during
excavation and grading. The type of equipment used generally depends on
the functions to be performed and on specific site conditions. Shaping
and compacting of the earth is an important part of site preparation.
Earthwork activities might require that fill material be used on the
site. In such cases, the fill must be spread in uniform, thick layers
and compacted to a specific density. An optimum moisture content must
also be reached. Graders and bulldozers are the most common earth-
spreading machines, and compaction is often accomplished with various
types of rollers. If rock is to be removed from the site, the
contractor must first loosen and break the rock into small pieces using
various types of drilling equipment or explosives. (Adapted from
Peurifoy, Robert L. and Oberlender, Garold D. (1989). Estimating
Construction Costs (4th ed.). New York: McGraw Hill Book Company.)
    Once materials have been excavated and removed and the ground has
been cleared and graded, the site is ready for construction of
buildings, roads, and/or other structures. During construction
activity, the disturbed land can remain exposed without vegetative
cover for a substantial period of time. Where the soil surface is
unprotected, soil particles and other pollutants are particularly
susceptible to erosion and may be easily washed away by rain or snow
melt and discharged from the site. Permittees typically use a
combination of erosion and sediment control measures designed to
prevent mobilization of the soil particles and capture of those
particles that do mobilize and become entrained in stormwater. In some
cases permittees treat a portion of the discharge using filtration or
other treatment technologies. Common erosion and sediment control
measures and treatment technologies are described further in the
Development Document.

V. Summary of the Proposed Regulation

    EPA published proposed regulations for the C&D category on November
28, 2008. 73 FR 72562. The proposed rule contained several options. One
option (Option 1), which is based on the requirements similar to those
contained in past EPA CGPs, would have established a set of non-numeric
effluent limitations requiring dischargers to provide and maintain
effective erosion control measures, sediment control measures, and
other pollution prevention measures to minimize, control or prevent the
discharge of pollutants in stormwater and other wastewater from
construction sites. In addition, reflecting current requirements in the
EPA CGP, sediment basins would have been required for common drainage
locations that serve an area with 10 or more acres disturbed at one
time to contain and settle sediment from stormwater runoff before
discharge. Option 1 would have required minimum standards of design for
sediment basins; however, alternatives that control sediment discharges
in a manner equivalent to sediment basins would have been authorized
where approved by the permitting authority.
    Another option (Option 2) would have incorporated the same
provisions as Option 1 and for sites of 30 or more acres located in
areas of the country with the annual Revised Universal Soil Loss
Equation (RUSLE) R-factor greater than 50 and that contained more than
10% by mass of soil particles smaller than 2 microns, discharges of
stormwater from the site would have been required to monitor and meet a
numeric effluent limitation on the allowable level of turbidity. The
numeric turbidity limitation proposed was 13 nephelometric turbidity
units (NTUs). The technology basis for Option 2 was active or advanced
treatment systems (ATS), which consisted of polymer-assisted
clarification followed by filtration. A third option (Option 3) was
similar to Option 2, except that it would have applied the 13 NTU
limitation to all construction sites of 10 or more acres, regardless of
location or soil type.
    In addition, the proposal presented and solicited comment on
another option that would require compliance with a higher numeric
turbidity effluent limitation (e.g., 50 to 150 NTU, or some other
value) based on passive treatment technologies instead of ATS (see 73
FR 72562, 72580-72582, 72610-72611). Passive treatment technologies
include conventional erosion and sediment controls, polymer addition to
sediment basins, fiber check dams with polymer addition, and other
controls. At proposal, EPA sought additional data on the performance of
passive treatment systems, and the cost and pollutant loading
reductions that would be attainable from such an option.
    In the proposed rule, EPA selected Option 1 as the basis of BPT and
BCT, and Option 2 as the basis of BAT and NSPS. At the time of
proposal, EPA defined a ``new source'' as any source from which there
will be a discharge associated with construction activity that will
result in a building, structure, facility, or installation subject to
new source performance standards elsewhere under 40 CFR subchapter N.
    A summary of the costs, estimated pollutant reductions, cost
effectiveness and monetized environmental benefits of the proposed
options are contained in the Federal Register notice for the proposed
rule, in the support

documents for the proposed rule and in the record.

VI. Summary of Major Comments Received

    EPA received numerous comments on the proposed rule. The majority
of comments centered on EPA's selection of ATS as the technology basis
for BAT and NSPS and the data and assumptions used to estimate the
numeric limitation, costs and pollutant load reductions of the proposed
BAT and NSPS. ATS is no longer the technology basis for BAT and NSPS in
the final rule.
    Some commenters argued that EPA's data used to estimate costs of
the proposed option based on ATS did not accurately consider all of the
costs, particularly for projects of longer duration. In response, EPA
revised the model project analysis to consider projects of longer
duration and utilized a unit-cost approach based on data contained in
the record for the proposal.
    Some commenters argued that EPA's analysis of the amount of
construction activity underestimated actual levels of construction
activity, since EPA's estimates were based on land use change estimates
from 1992 to 2001 using the National Land Cover Dataset (NLCD). In
response, EPA revised estimates of annual acres subject to the
regulation using industry economic data instead of the NLCD data.
    Some commenters argued that EPA's data and assumptions used to
estimate loading reductions of the regulatory options did not
accurately account for current controls in place nationwide. In
response, EPA revised the assumptions used in the model to account for
baseline controls. EPA also used data at the watershed level for some
modeling parameters.
    Some commenters requested that numeric limitations be based on, or
consider, the background levels of sediment and turbidity in receiving
streams when establishing a turbidity limitation. EPA notes that BAT
and NSPS are based on the capabilities of technology, not receiving
water quality. It would not be appropriate in establishing technology
based effluent limitations pursuant to CWA sections 301 and 306 for EPA
to consider the water quality of specific water bodies. See
Weyerhaeuser Co. v. Costle, 590 F.2d 1011, 1040-1044 (D.C. Cir. 1978).
Permitting authorities have the ability to develop water-quality based
effluent limitations to address receiving water concerns. Some states
have set limitations for specific projects considering the background
turbidity of the receiving waters. Commenters further argued that
discharges of low turbidity water to streams that are naturally high in
turbidity could contribute to stream instability. EPA does not agree
with this comment. The particles contained in stormwater discharges
from construction sites are primarily fine-grained, since sediment
controls remove the bulk of the coarser particles. These fine-grained
particles are not beneficial from a stream stability standpoint.
Therefore, removal of these particles from the stormwater discharge
would not be expected to further contribute to stream instability, if
the receiving stream was already unstable. It is plausible that
discharge of a large volume of stormwater over a short period of time
to a small stream with a high natural sediment load could contribute to
instability. If this condition were to exist, it could be alleviated
simply by controlling the rate of discharge or by dispersing runoff to
vegetated areas on site, if available (see also, comment by Dr. Britt
Faucette, EPA-HQ-OW-2008-0465-0527 in the rulemaking record).
    Some commenters argued that some of the data EPA used to determine
the numeric effluent limitation based on ATS should not be used because
EPA lacked specific information on factors, such as type of
construction project or treatment system configuration. Commenters also
argued that the data was not representative, since these data were
primarily from the Northwest United States. EPA does not agree with
these comments. The data represent a variety of project types. Although
EPA may not have detailed information about specific aspects of some
projects (such as project size and treatment system flow rate), EPA has
conducted an engineering review of the data and determined that the
data is representative. EPA has excluded data, where appropriate, to
account for factors such as treatment system startup and variation
outside of the range that EPA would consider indicative of proper
operation. Details of the engineering review of the data can be found
in the Development Document. In addition, EPA received additional
information on some of the data, such as project type and treatment
configuration. EPA also received data from additional projects,
including projects in New York and North Carolina. More details on the
data can be found in the administrative record.
    Some commenters were concerned about the non-numeric effluent
limitations proposed, and specifically questioned whether some of the
proposed requirements could be implemented on all construction sites.
EPA generally agrees that some of the requirements, as proposed, could
not be implemented on all sites and made revisions to the non-numeric
effluent limitations to make them applicable to all sites. For certain
controls, EPA included ``unless infeasible'' to recognize that there
may be some sites where a particular control measure cannot be
implemented, thus allowing flexibility for permittees. (See Section
X.B.)
    Some commenters questioned the stringency of the proposed soil
stabilization requirements, and were concerned about the costs and
feasibility of initiating stabilization of disturbed area
``immediately'' when final grade is reached or any clearing, grading,
excavating or other earth disturbing activities have temporarily or
permanently ceased and will not resume for a period exceeding 14
calendar days. EPA disagrees that this requirement is not feasible.
Given the importance of soil stabilization techniques (see Chapter 5 of
the Technical Development Document (TDD)), and the influence of soil
cover on soil erosion rates, EPA has determined that initiating soil
stabilization measures immediately is an important non-numeric effluent
limitation. EPA sees no compelling reason why permittees cannot take
action immediately to stabilize disturbed soils on their sites. Erosion
control measures, such as mulch, are readily available and permittees
need only plan accordingly to have appropriate materials and laborers
present when needed. EPA has, however, modified this requirement for
clarity (see the final requirement at Sec.  450.21(b).
    EPA received comments concerning applicability of the final rule to
linear construction projects, including the numeric effluent
limitation. EPA considered the unique characteristics of linear
projects in determining the appropriate technology based effluent
limitations for those sites. The final rule, in part based on the
considerations of linear projects, no longer contains a requirement to
install a sediment basin (See Section VII.A), the technology basis for
the numeric effluent limitation is no longer ATS (See Section X.G.3),
and revisions were made to the non-numeric effluent limitations based
on comments concerning the feasibility at linear projects. (See Section
X.B.2). EPA disagrees with comments that suggested EPA should either
exempt all linear projects from the final rule or from the numeric
effluent limitation. EPA has determined that numeric effluent
limitations are feasible for linear projects and passive treatment
systems provide flexibility to linear projects to

take into account site specific considerations. (See the TDD for
specific examples of the utilization of passive treatment systems at
linear projects). Additionally, EPA believes that the permitting
authority should exercise discretion when determining the monitoring
locations and monitoring frequency for linear construction projects.
(See Section XIX.A).
    Based on the unique regulatory circumstances of interstate natural
gas pipeline construction projects EPA has chosen not to have the
numeric limitation and monitoring requirements at 40 CFR 450.22(a)
apply to the discharges associated with the construction of natural gas
pipelines. This exemption only applies to discharges associated with
construction of interstate natural gas pipelines that are under the
jurisdiction of the Federal Energy Regulatory Commission (FERC). EPA
determined this was appropriate due to the comprehensive regulatory
program that FERC requires and enforces for the construction of these
projects. Through its program, FERC requires a variety of erosion and
sediment controls to be implemented during construction, some of which
are more stringent than those contained in today's rule. FERC conducts
site-specific reviews to establish the allowable area of disturbance
for project construction and dictates the manner in which construction
of these projects can proceed. Typical requirements would include
minimizing the amount of time that soils are allowed to be exposed,
managing the discharges from trench dewatering, limiting the amount of
vegetation that can be cleared adjacent to streams and wetlands, and
requiring successful revegetation of project areas. FERC has been
requiring these projects to implement its erosion and sediment control
program since 1989. Thus, it is a well-developed regulatory program
that includes stringent requirements, oversight, public participation,
and onsite inspection. EPA does not want to limit the flexibility of
FERC to implement its program by imposing numeric limitations on these
unique projects.
    EPA received comments encouraging the Agency to include controls in
the final rule on stormwater discharges that occur after construction
activity has ceased or what they call ``post-construction'' stormwater
discharges. These discharges are outside the scope of the final rule;
however the Agency understands that there is a need to address
discharges from newly developed and redeveloped sites, such as
commercial buildings, roads, or parking lots, in order to protect the
water quality of our nation's waters. As the urban, suburban and
exurban human environment expands, there is an increase in impervious
landcover and stormwater discharges. This increase in impervious
landcover on developed property reduces or eliminates the natural
infiltration of precipitation. The resulting stormwater flows across
roads, rooftops and other impervious surfaces, picking up pollutants
that are then discharged to our nation's waters. In addition, the
increased volume of stormwater discharges results in the scouring of
rivers and streams; degrading the physical integrity of aquatic
habitats, stream function and overall water quality. In July 2006, EPA
commissioned the National Research Council (NRC) to review the Agency's
program for controlling stormwater discharges under the CWA and
recommend steps the Agency should take to make the stormwater program
more effective in protecting water quality. The NRC Report Urban
Stormwater Management in the United States (DCN 42101) states that
stormwater discharges from the built environment remain one of the
greatest challenges of modern water pollution controls, ``as this
source of contamination is a principal contributor to water quality
impairment of waterbodies nationwide.'' The NRC report found that the
current regulatory approach by EPA under the CWA is not adequately
controlling all sources of stormwater discharges that are contributing
to waterbody impairment. NRC recommended that EPA address stormwater
discharges from impervious landcover and promote practices that
harvest, infiltrate and evapotranspirate stormwater to prevent it from
being discharged, which is critical to reducing the pollutant loading
to our nation's waters.
    EPA has committed to and begun a rulemaking addressing stormwater
discharges from newly developed and redeveloped sites under CWA section
402(p). EPA has published a draft Information Collection Request, 74 FR
56191 (October 30, 2009) for public comment that will seek information
and data to support the rulemaking, and plans to complete this rule in
the fall of 2012.
    Some commenters argued that turbidity is not a ``pollutant'' under
the CWA. EPA disagrees with the commenters as turbidity is a
``pollutant'' under the CWA and an indicator for other pollutants and
is the appropriate pollutant in this rule to control, under the
appropriate levels of technology, for discharges from C&D sites. In
this rule, turbidity is being regulated as a nonconventional pollutant
and as an indicator pollutant for the control of other pollutants in
discharges from C&D sites including metals and nutrients. By providing
a measure of sediment and other pollutants in discharges, turbidity is
an indicator of the degree to which sediment and other pollutants found
in discharges are reduced. Turbidity is also a more effective measure
of the presence of fine silts and clays and colloids, which are the
particles in stormwater discharges that EPA is primarily targeting in
today's rule.
    Turbidity is a pollutant as that term is defined in the CWA. See
e.g., Conservation Law Foundation v. Hannaford Bros. Co., 327 F.Supp.2d
325, 326 (D.Vt. 2004), aff'd 139 Fed.Appx. 338 (2d.Cir. 2005). The CWA
defines ``pollutant'' broadly to include ``dredged spoil, solid waste,
incinerator residue, sewage, garbage, sewage sludge, munitions,
chemical wastes, biological materials, radioactive materials, heat,
wrecked or discarded equipment, rock, sand, cellar dirt and industrial,
municipal and agricultural waste.'' CWA section 502(6). See NRDC v.
EPA, 822 F.2d 104, 109 (D.C.Cir. 1987) (``The term `pollutant' is
broadly defined[hellip]''); U.S. v. Hamel, 551 F.2d 107, 110 (6th Cir.
1977) (noting that the definition is set forth in ``broad generic
terms.''). EPA describes ``turbidity'' as ``an expression of the
optical property that causes light to be scattered and absorbed rather
than transmitted with no change in direction of flux level through the
sample caused by suspended and colloidal matter such as clay, silt,
finely divided organic and inorganic matter and plankton and other
microscopic organisms.'' 40 CFR 136.3; 72 FR 11200, 11247 (March 12,
2007). Turbidity fits easily into the broad definition of pollutant.
The definition of pollutant is not limited to those terms that are
specifically listed in the statute at section 502(6). See NWF v.
Gorsuch, 693 F.3d 156, 174 n.56 (D.C. Cir. 1982); Sierra Club v. Cedar
Point Oil Co., 73 F.3d 546, 565 (5th Cir. 1996).
    Turbidity is also an indicator or measurement of other pollutants
in the water body; however merely because turbidity measures other
pollutants or can be an expression of the condition of the water body,
does not mean it is not itself a ``pollutant'' under the CWA. There are
numerous other pollutants, some that Congress explicitly included in
the CWA, that are also indicators or measurements of other pollutants.
For example, the CWA lists biochemical oxygen demand (BOD) and pH as
pollutants. CWA section 304(a)(4). BOD is the measure of the amount of
oxygen required by bacteria for stabilizing

material that can be decomposed under aerobic conditions and pH is a
measure of how acidic or basic a substance is. Additionally, chemical
oxygen demand (COD) is a pollutant and a measurement of other
pollutants. See BASF Wyandotte v. Costle, 598 F.2d 637, 651 (1st Cir.
1979). Even total suspended solids (TSS) are a measure of the organic
and inorganic particulate matter in wastewater. Like turbidity, there
is no question BOD, pH, COD and TSS are pollutants and there is no
conflict between a pollutant being a measurement of other pollutants
and a pollutant itself under the CWA.
    One commenter argued that turbidity is a direct representation of
TSS, thus, if anything, turbidity can only be used as a surrogate for
TSS, and thus a conventional pollutant. In 1978 EPA interpreted
``suspended solids,'' at section 304(a)(4), as ``total suspended solids
(non-filterable) (TSS).'' EPA defined TSS as ``a laboratory measure of
the organic and inorganic particulate matter in wastewater which does
not pass through a specified glass filter disk.'' See 40 CFR 401.16; 43
FR 32857, 32858 (July 28, 1978). The terms turbidity and TSS are
related to sediment and are analogous, but they are not synonymous
pollutants or measures of water quality. TSS and turbidity are measured
differently, as turbidity is a measure of the light scattering
properties of the sample measured as NTU and TSS is generally a measure
of the concentration (i.e., milligrams per liter). The size, shape, and
refractive index of suspended particulate matter are not directly
related to the concentration and specific gravity of the suspended
matter. Therefore, measurements of TSS and turbidity are not
interchangeable. Pollutants that are not identified as either toxic or
conventional pollutants are nonconventional pollutants under the CWA.
See CWA section 301(b)(2)(F); 304(a)(4); 40 CFR 401.16; Rybacheck v.
EPA, 904 F. 2d 1276, 1291-92 (9th Cir. 1990). CWA section 304(a)(4)
identifies what pollutants are conventional pollutants under the CWA,
namely biochemical oxygen demand, suspended solids, fecal coliform, and
pH, with EPA adding oil and grease. See also, 40 CFR 410.16; 44 FR
44501 (July 30, 1979). Turbidity is not identified as a conventional
pollutant in the CWA or been identified as one by EPA. In the proposal,
EPA cited to Rybachek v. EPA, 904 F.2d at 1291-92, to demonstrate an
analogous situation where it was argued that ``settleable solids'' were
a component of TSS, or in other words, they are the same pollutant,
thus EPA should have classified settleable solids as a conventional
pollutant rather than a nonconventional pollutant. Id. at 1291. The
Ninth Circuit, agreeing with EPA's analysis in that case and the
discussion above, concluded that ``because settleable solids were not
designated by Congress as either conventional or a toxic pollutant,
they should be considered a nonconventional pollutant under [section
301(b)(2)(F)].'' Id. at 1292. EPA applied a similar analysis to
turbidity to conclude that it is a nonconventional pollutant under the
CWA.
    Commenters' focus on arguing that turbidity is not a pollutant, or
at the very least a conventional pollutant, may be based on a desire
for a different technology standard applied to this rulemaking (i.e.,
BCT). However, even if EPA did agree that turbidity is not a pollutant
or is a conventional pollutant, TSS and turbidity are not the only
pollutants of concern in discharges from C&D sites. Metals, nutrients,
and other toxic and nonconventional pollutants are naturally present in
soils, and can be contributed during construction activity or by
activities that occurred at the site prior to the construction activity
(see, e.g., comment from Dr. Britt Faucette, EPA-HQ-OW-2008-0465-0527
in the rulemaking record. EPA recognizes that its understanding of the
nature of stormwater discharges associated with construction activity
has evolved. However, as early as 1990, in the Phase I stormwater
rulemaking EPA identified nonconventional and toxic pollutants of
concern in discharges from construction sites stating ``[c]onstruction
sites can also generate other pollutants such as phosphorus, nitrogen,
and nutrients from fertilizer, pesticides, petroleum products,
construction chemicals and solid wastes.'' 55 FR at 48033. The National
Academy of Sciences agrees with EPA and the NRC report states ``[t]he
pollutant parameters of concern in stormwater discharges from
construction activity are TSS, settleable solids, turbidity, and
nutrients from erosion; pH from concrete and stucco; and a wide range
of metallic and organic pollutants from construction materials,
processes, wastes, and vehicles and other motorized equipment.'' NRC at
541. EPA is making clear in this final rule that while conventional
pollutants are a concern in discharges from construction sites, there
are also nonconventional and toxic pollutants of concern in discharges
from these sites. Many of these pollutants are present as particulates
and will be removed with other particles. Dissolved forms of pollutants
are often absorbed or adsorbed to particulate matter and can also be
removed along with the particulates (i.e., sediment). See the
Environmental Assessment document for additional discussion about
pollutants found in discharges from C&D sites.
    Additionally, stormwater discharges from C&D sites in their
entirety are ``industrial waste,'' a nonconventional pollutant under
the CWA, thus EPA is not obligated to single out specific constituents
or parameters in the discharge. See Northern Plains Resource Council v.
Fidelity Exploration and Development Co., 325 F.3d 1155 (9th Cir.
2003). Due to stormwater discharges being, or including,
nonconventional or toxic pollutants, EPA is statutorily obligated to
promulgate a BAT level of control for these point source discharges.
CWA section 301(b)(2)(A). EPA is also statutorily obligated to
promulgate a best available demonstrated control technology (BADT) for
NSPS for all pollutants from new sources, even if the only pollutants
from C&D sites were conventional pollutants.
    Some commenters urged EPA to establish numeric effluent limitations
for pollutants other than turbidity (such as pH). While EPA agrees
there are other pollutants of concern that are discharged from
construction sites the Agency determined it is not necessary to
establish any other numeric effluent limitations at this time. Many of
the pollutants of concern are sediment-bound pollutants, such as metals
and nutrients. The non-numeric effluent limitations in the final rule
will address the mobilization of sediment and the discharge of these
sediment-bound pollutants. The final rule includes a non-numeric
effluent limitation that prohibits the discharge of wastewater from
washout of concrete, unless managed by an appropriate control. 40 CFR
450.21(3)(1). This requirement was included to specifically address
concerns with pH. Additionally, the numeric effluent limitation, in
addition to controlling the discharge of turbidity, will control the
discharge of some of these other pollutants of concern. If permitting
authorities have concerns regarding the discharge of other pollutants
they may be addressed with numeric effluent limitations on case-by-case
basis through NPDES permits.
    Some commenters noted that they believed there may be environmental
risks of applying polymers during construction activity to control
discharges of pollutants from C&D sites due to what commenters believed
was the potential for the polymers to cause fish kills or otherwise
cause an adverse

effect in the receiving waters. At proposal EPA had no specific
examples of the use of treatment chemicals causing fish kills or
aquatic toxicity, although anecdotal evidence did exist (see DCN
41110). In the proposal, EPA specifically requested information and
data that quantified the number of instances where overuse of polymers
occurred, the circumstances resulting in such overuse, and the actual
or potential environmental impacts associated with such events. 73 FR
at 72573; see also 73 FR at 72610. EPA received one specific comment
regarding a fish kill associated with the use of ATS (see EPA-HQ-OW-
2004-0465-1287 in the rulemaking record) and one comment that
referenced ``significant environmental harm'' resulting from the use of
chitosan or other chemicals, although specific details were not
provided (see EPA-HQ-OW-2008-0465-0973 in the rulemaking record). One
commenter also stated that during pilot testing of two ATS systems that
``chemical overuse and poor operation never purposefully occurred, but
happened anyway.'' This commenter also noted, when comparing ATS usage
during this pilot testing to ATS that is used in Washington State that
``the treatment system used on the Idaho site was missing many features
that made it easier and environmentally safer to operate. The operator
did not have the level of training required in Washington. DEQ did not
come close to the amount of staff time Washington spends overseeing the
operation of these systems and DEQ did not have any staff trained to
assess if the system was being operated correctly.'' (see EPA-HQ-OW-
2008-0465-1269 in the rulemaking record.
    A number of coagulant and flocculants, including polymers, are
available on the market and are in wide use for the control of
pollutants, not only on construction sites, but to reduce sediment from
agricultural fields and to reduce pollutants in discharges from
wastewater treatment plants to name a few. While successful in reducing
sediment and turbidity in conveyance systems, polymers and other
additives should be carefully utilized in passive treatment systems.
Several states have approved specific formulations for use on
construction sites and EPA will work with the permitting authorities
and the construction industry to ensure the proper application of
polymers and other additives, if necessary, before owners and operators
of construction sites are required to meet the numeric effluent
limitation. Knowledge from toxicity studies suggest that polymers are
highly variable as to their toxic effects on aquatic organisms (see
discussion of toxicity in the Environmental Assessment). States have
approved the use of polymers and other additives at construction sites,
for example, Washington State has approved chitosan, a cationic
polysaccharide biopolymer, for certain uses and has seen wide use in
water and stormwater treatment. Therefore, the use of specific
compounds should be considered by the permitting authority and owners
and operators of construction sites in light of various environmental
influences. While EPA recognizes that there is the potential for
problems due to improper application of polymers, EPA has determined
that when properly used, environmental impacts from polymers or
flocculants should not occur through the use of passive treatment
systems. The dose ranges where polymers are utilized on construction
sites are well below the chronic toxicity levels. The utilization of
polymers on construction sites has occurred for a significant period of
time and they are currently being used on construction sites throughout
the nation. EPA recognizes the merits of ensuring that polymers or
other chemical additives, if necessary, are properly used. Permitting
authorities should carefully consider the appropriateness of usage of
these materials where there are sensitive or protected aquatic
organisms in the receiving waters, including threatened or endangered
species and their critical habitat. NPDES permitting authorities may
establish controls on dosage and usage, protocols for residual toxicity
testing, require prior approval before the use of particular polymers,
training requirements for site operators or other measures they deem
appropriate. In addition, permittees can also specify, and permittees
may choose to utilize, on-site infiltration or dispersion to vegetated
areas in combination with, or in place of, polymer-based systems. See
73 FR 72562, 72573-74. Based on the information in the record EPA has
determined that when polymers are properly applied the risks of
toxicity to aquatic life or adverse effects to the receiving water are
minimal. However, it is important that permittees be properly trained
in the use of polymers. Operators of C&D sites need to have expertise
in a number of technical areas, including engineering, stormwater
management and implementation of erosion and sediment controls.
Technical specialists, such as engineers, hydrologists and soil
scientists are involved in many aspects of site design and construction
activity. Permittees typically have engineers on staff, or employ
consultants to prepare plans, supervise construction and conduct
inspections of various aspects of the project. Given that construction
activities require rigorous attention to safety and engineering
specifications, there is a reasonable basis for EPA to expect that
operators can conform to proper operation and maintenance of controls
and proper use of polymers and flocculants. The erosion and sediment
control and stormwater management industries are large and composed of
diverse specialties. There are several national trade and professional
organizations whose members are engaged in various aspects of erosion
and sediment control and stormwater management and who have an active
role in conducting research and technical outreach. EPA believes that
there is a range of expertise available across the industry to properly
implement controls that may be required to meet a numeric limitation.
Also, sampling and compliance with the turbidity limitation is not
required until 18 months after the effective date of this final rule
for sites with 20 or more acres of disturbed land at one time and four
years after the effective date of the final rule for sites with 10 or
more acres of disturbed land at one time. This will allow permittees
time to obtain any necessary training if they do not already have
trained personnel on staff and for the permitting authorities to
provide guidance to permittees.

VII. Summary of Significant Decisions and Revisions to Analyses

    EPA solicited comments on a number of issues in the proposed rule.
Two areas that EPA specifically requested comments on were the
regulatory options proposed as well as the data used to estimate the
costs, pollutant loading reductions, environmental benefits and
economic impacts of various options. Based on comments received, EPA
revised the regulatory options that were proposed and further developed
a regulatory option that would establish a numeric limitation based on
passive, rather than active, treatment at construction sites. EPA used
data collected in support of the proposed regulation, data submitted
during the public comment period and by the public after the close of
the comment period, as well as additional data collected by EPA to
estimate costs, environmental benefits and economic impacts for this
option. EPA also updated its costs and economic analyses with these new
data to revise the estimates for the proposed options. EPA

also revised what C&D sites may be new sources and covered by NSPS.
This section summarizes the principle regulatory options considered for
the final rule and the revisions that were made to EPA's analyses
following proposal.

A. Regulatory Options

    In considering options for the final rule, EPA revised the proposed
regulatory options in several ways. First, comments received by state
environmental agencies, Departments of Transportation (DOTs), the U.S.
DOT, and other members of the public indicated that sediment basins are
not common practice on all larger construction sites, particularly on
linear projects such as road and highway construction. The reasons
provided by commenters included the lack of available space within the
project right of way as well as the preference to use distributed
controls on some sites instead of centralized drainage at sites.
Commenters also stressed the need to allow engineers and other
professionals that are designing erosion and sediment control plans to
choose practices that reflect site-specific factors, and that mandating
basins for larger sites would limit that flexibility. Commenters also
suggested that active treatment, which typically involves construction
of storage basins, was a disincentive to using distributed stormwater
controls to manage long-term stormwater discharges from newly developed
and redeveloped sites. If permittees construct sediment basins,
according to commenters, they are more likely to retain these basins as
part of the long-term stormwater management controls. EPA agrees with a
number of these comments, particularly the need to give professionals
the flexibility to design site-specific controls. Therefore, EPA
deleted the sediment basin sizing requirements that were contained in
the proposed Options 1, 2 and 3 when considering options for the final
rule. Commenters also indicated that the soil clay content provisions
proposed by EPA for Option 2 would be difficult to implement, given the
variation in soils present at construction sites and the fact that
imported soils are often used for fill material. A concern was also
raised on the practical applicability of the clay content provision to
linear construction projects that may exist over large geographic
areas. Therefore, determination of whether or not a particular project
would meet the soil clay content thresholds would be difficult for
owners and operators of construction sites. EPA agrees with commenters
on this issue. Therefore, EPA deleted the soil clay content threshold
from Option 2. Commenters also suggested that the R-factor criteria
proposed under Option 2 would represent one more unnecessary complexity
to the regulation, and that the site size criteria should be based on
the disturbed area of the site, not the total project size since
stormwater discharges from disturbed areas are the primary discharges
containing pollutants. EPA agrees with these suggestions. Therefore,
EPA also deleted the R-factor criteria from Option 2. The revised
Option 2 would apply to any site that met the disturbed acreage size
threshold, regardless of soil type and R-factor.
    Comments from the potentially regulated industry and states on the
proposal did not favor the use of ATS as the technology basis for a
national turbidity limitation. There were a number of reasons given,
but the most prominent included the costs, availability and feasibility
of ATS. While EPA does not agree with all of these comments, the Agency
further evaluated data available to support a numeric turbidity
limitation based on technologies other than ATS, including techniques
that incorporate either liquid or solid forms of polymer. Examples
include liquid polymer dosing of sediment basins, passive dosing in
channels through the use of polymer gel socks or floc-blocks or floc-
logs, and application of polymer to fiber check dams. EPA also
evaluated data available for the placer mining industry. EPA determined
that a numeric turbidity limitation based on these and other passive
treatment techniques are technically available. As a result, EPA
further explored this option and looked at site size thresholds of 1, 5
and 10 acres of disturbed land at one time as potential applicability
criteria for a technology-based numeric limitation based on passive
treatment.
    EPA also received numerous comments about the feasibility of many
of the erosion and sediment control and pollution prevention provisions
contained in Options 1, 2 and 3. EPA generally agrees that some of
these requirements, as proposed, could not be implemented on some
construction sites. As a result, EPA made several changes to these
provisions which are described in more detail in section X.B.

B. Cost Analysis

    EPA received several comments regarding the costs of ATS and the
methodology used by EPA to determine costs of the regulatory options.
While EPA believes some of these comments have technical merit, EPA
found that some commenters greatly overestimated the likely actual
costs to implement ATS. Key points made by commenters included (1) that
the methodology used at proposal, which was based on a flat cost per
gallon to treat, likely did not capture the actual costs of ATS in some
applications and in some areas of the country; (2) that the methodology
did not factor in the longer duration of some projects (particularly
larger residential projects); and (3) the methodology for estimating
the size of the industry, which was based on land use change data from
1992 to 2001, likely did not accurately predict the level of
construction activity in the near future that would be expected under
normal business conditions (i.e., not reflective of the current
downturn in the industry), which is the primary analysis case upon
which EPA based costs and economic impacts (see discussion in Section
XII). EPA has revised and updated the methodology used to estimate the
costs of ATS and the expected amount of construction activity to
reflect these and other points. The revised analysis significantly
increased costs for the revised Options 2 and 3. In the updated
methodology, EPA first used data submitted by vendors to develop a
series of one-time and monthly costs for ATS. Secondly, EPA estimated
the expected amount of construction activity using long-term industry
economic data. EPA then estimated the expected duration of projects of
varying site size and project types using permit Notice of Intent (NOI)
data from approximately 22,000 permit applications from 4 States for
construction activities occurring primarily between 2003 and 2009. The
combination of all three of these factors (a unit costing approach,
longer durations for some projects and a higher estimate of total acres
being developed) resulted in significantly higher costs for the revised
Options 2 and 3 than were estimated at the time of proposal. Moreover,
the cost of the revised Option 2 increased over the proposed Option 2
because EPA removed the R-factor and soil type criteria of proposed
Option 2, thereby increasing the number of projects covered by revised
Option 2. Additional details can be found in the Development Document
and in the Economic Analysis.

C. Pollutant Load Analysis

    EPA received several comments on the pollutant loading analysis
contained in the proposal, primarily stating that EPA overestimated
baseline pollutant loadings and the reductions due to Options 2 and 3
because the assumptions used in EPA's model did

not accurately account for current industry practices. EPA generally
agrees with some of these comments, and has revised the assumptions
used in the model. EPA also used a more detailed analysis of loads for
the final rule that uses watershed-specific data for some of the model
parameters. The result of these changes is that the load reduction
estimates for Options 2 and 3 have decreased since proposal. Additional
details on the new assumptions and the results of EPA's analysis can be
found in Section XV and in the Development Document.

D. Economic Analysis

    The primary revisions to the economic analysis were updates to the
approach to developing model projects and then the assignment of
project costs to model firms. EPA revised the model projects to include
a set of 288 model projects, based on 12 different size categories, 12
duration categories, and two project types (building, transportation).
EPA also accounted for the effect that different climate and soil
conditions can have on control costs by considering variation in
rainfall and runoff factors for each state. This resulted in 14,688
model projects with potentially different costs. These model projects
were then combined with activity estimates to develop an estimated
84,000 individual model projects.
    Another revision to the economic analysis was the way in which
project costs were assigned to firms. For the proposal, project costs
were used to develop a weighted average cost per acre for each state.
These weighted average costs were then assigned to model firms based on
the estimated number of acres they construct on per year. For the final
rule, each of the 84,000 projects and their associated costs were
assigned to firms. This assignment was based on each category of model
firm's capacity to perform projects of various size and duration.
    EPA also made changes to the adverse case analysis and the analysis
of future costs. EPA received comments that the data used to represent
adverse business conditions for the adverse case analysis did not
adequately represent the most recent conditions for the industry, which
are less favorable. EPA addressed this concern by updating the adverse
analysis industry financial profile with 2008 Value Line financial
data. For the future costs analysis, EPA was able to use future revenue
projections published by Global Insights, to estimate year to year
changes in acreage developed, the total number of projects and the
number of projects subject to various rule requirements. This allowed
for an assessment of changes in the number of firm and employment
impacts from year-to-year.
    EPA made two adjustments to the housing affordability analysis. For
the proposal, EPA evaluated the effect of the proposed options on the
price of the median and lower quartile homes. For the final rule, EPA
evaluated the impacts of potential price increases for a new home
selling for $100,000 and $50,000 to better reflect the impact of price
increases at the very low end of the market for new housing. For the
proposal, all new home buyers were assumed to buy the most expensive
house they could qualify to purchase. However, for the final rule EPA
was able to use data from the American Housing Survey, to estimate the
average percentage of household income typically spent on a home
purchase, for various income ranges. This allowed for a more realistic
assessment of the number of home buyers who may have difficulty
affording a new home after a price increase.

E. Benefits Estimation and Monetization

    Although EPA is not required by statute to quantify environmental
benefits for ELGs and NSPSs, EPA did quantify and monetize benefits of
the regulatory options to comply with Executive Order 12866. EPA
solicited comments on the proposed approach. EPA received comments on
the approach and made revisions in order to improve upon the estimates
prepared at proposal. Soil on construction sites contains a number of
pollutants beyond sediment and turbidity. EPA estimated the degree to
which the regulatory options would decrease nitrogen and phosphorus
levels in receiving surface waters, and estimated associated water
quality impacts using the nitrogen and phosphorus versions of the
Spatially Referenced Regressions on Watershed Attributes (SPARROW)
model. EPA used these estimates to inform the estimation of the degree
to which the public is willing to pay for water quality improvements
associated with the regulatory options, which in turn was utilized in
EPA's monetized benefits analysis.
    EPA expanded the set of potentially impacted waters to include a
subset of the nation's estuaries. This enabled the agency to analyze
the degree to which the public is willing to pay for improvements in
estuarine water quality. EPA utilized this information in conjunction
with available data on improvements in estuarine water quality
associated with each of the regulatory options in order to monetize
benefits associated with those options.
    EPA also made refinements to the Water Quality Index (WQI) used for
mapping pollution parameter changes to effects on human uses and
support for aquatic and terrestrial species habitat. Implementation of
the WQI involves transforming the measurements of parameter, such as
TSS, nitrogen, and phosphorus, into sub-index values that express water
quality conditions on a common scale of 0 to 100. For the pollutant
TSS, a unique sub-index curve was developed for each of the 85 Level
III ecoregions using baseline TSS concentrations calculated in SPARROW
at the enhanced Reach File 1 (RF1) level (see Section XV). In addition,
at proposal, EPA did not quantify projected reductions in nutrient
loadings as a result of the rule, but these were included in the final
rule analysis, including the assessment of changes in the WQI.

VIII. Characteristics of Discharges Associated With Construction
Activity

    Construction activity typically involves clearing, grading,
excavating and other land-disturbing activities. Prior to construction
activity, these land areas may have been agricultural, forested or
other undeveloped lands. Construction activity can also occur as
redevelopment of existing rural or urban areas, or infill development
on open space within existing developed areas. The nature of
construction activity is that it changes, often significantly, many
elements of the natural environment. As described earlier, construction
activities typically involve clearing the land of vegetation, digging,
and earth moving and grading, followed by the active construction
period when the affected land is usually left denuded and the soil
compacted, often leading to an increase in the peak discharge rate and
the total volume of stormwater discharged and higher rates of erosion.
During the land disturbance period, affected land is generally exposed
after removal of grass, rocks, pavement and other protective ground
covers. Where the soil surface is unprotected, colloids, silt, clay and
sand particles may be easily picked up by wind and/or washed away by
rain or snow melt.
    Stormwater discharges can have variable levels of pollutants.
Available data show that turbidity levels in discharges from
construction sites range from as low as 10-50 NTU to tens of thousands
of NTU. When the denuded and exposed areas contain nutrients,
pathogens, metals or organic compounds, these other pollutants are
carried at increased rates (relative to

discharges from undisturbed areas) to surrounding waterbodies via
stormwater and other discharges (e.g., inadequately controlled
construction equipment wash water). Discharges of these pollutants from
construction activities can cause changes in the physical
characteristics of waterbodies, such as pH or water temperature as well
as changes in biological characteristics such as aquatic species
abundance, health and composition. Changes in stream flow regime can
also occur due to deposition of sediment, as well as the altered
watershed hydrology resulting from soil compaction and loss of
infiltrative capacity.
    Discharges from C&D sites associated with construction activity
have been documented to increase the loadings of several pollutants in
the receiving water bodies. The most prominent and most widespread
pollutants of concern discharged from C&D sites are turbidity,
suspended solids, total suspended solids (TSS), and settleable solids.
Each of these pollutants are indicators of solids contained in the
discharge (which, in the case of stormwater discharges associated with
construction activities, are primarily due to soil particles), and each
of these measures quantify different fractions of these solids.
    Discharges associated with construction activity are also expected
to contain varying concentrations of metals and toxic organic
compounds, some of which may be contributed by equipment used onsite
for grading and other construction activities, as well as various
construction materials used on-site (such as asphalt sealants, copper
flashing, roofing materials, adhesives, and concrete admixtures).
Metals are also naturally present in soils and, by removing vegetative
cover and increasing erosion and sediment loss, there will likely be an
increase in the amount of metals discharged from the C&D site. Metals
can also be present as a contaminant from previous activity on the site
(such as may occur in redevelopment of industrial areas) or as a
contaminant or additive in fertilizers and other soil amendments. Fuels
and lubricants are maintained onsite to refuel and maintain vehicles
and equipment used during construction activities. These products,
should they come in contact with stormwater and other site discharges,
could contribute toxic organic pollutants. Pathogenic pollutants can be
present in stormwater that comes into contact with sanitary wastes
where portable sanitation facilities are poorly located or maintained.
Also, trash and other municipal solid waste can be carried away by
stormwater.
    Nutrients can be present in construction site discharges, either as
naturally-occurring components of the soil or due to previous
activities on the site, such as enrichment due to agricultural
activities. In addition, activities during construction activity, such
as hydroseeding, can increase nutrients levels in the soil.

IX. Description of Available Technologies

A. Introduction

    As described in Section VIII, construction activity results in the
discharge of pollutants to waters of the U.S. These discharges can be
controlled by applying site design techniques that preserve or avoid
areas prone to erosion and through the effective use of a combination
of erosion and sediment control and pollution prevention measures.
Construction activities should be managed to reduce erosion and retain
sediment and other pollutants in the soil at the C&D site. Erosion and
sedimentation are two separate processes and the practices to control
them differ. Erosion is the process of wearing away of the land surface
by water, wind, ice, gravity, or other geologic agents. Sedimentation
is the deposition of soil particles, both mineral and organic, which
have been transported by water, wind, air, gravity or ice (adapted from
North Carolina Erosion and Sediment Control Planning and Design Manual,
September 1, 1988).
    Erosion control measures are intended to minimize dislodging and
mobilizing of sediment particles. Sediment control measures are
controls that serve to capture particles that have mobilized and are
entrained in stormwater, with the objective of removing sediment and
other pollutants from the stormwater discharge. An overview of
available technologies and practices is presented below; see the
Development Document for more complete descriptions. Many states and
local governments and other entities have also published detailed
manuals for erosion and sediment control measures, and other stormwater
management practices.

B. Erosion Control Measures

    The use of erosion control measures is widely recognized as the
most important means of limiting soil detachment and mobilization of
sediment. The controls described in this preamble are designed to
reduce mobilization of soil particles and minimize the amount of
sediment and other pollutants entrained in discharges from construction
activity. Erosion can be minimized by a variety of practices. The
selection of control measures that will be most effective for a
particular site is dictated by site-specific conditions (e.g.,
topography, soil type, rainfall patterns). The main strategies used to
reduce erosion include minimizing the time bare soil is exposed,
preventing the detachment of soil and reducing the mobilization and
transportation of soil particles off-site.
    Decreasing the amount of land disturbed can significantly reduce
sediment detachment and mobilization directly from ground disturbance
or indirectly through changes in overland flows. Minimizing site
disturbance by minimizing the extent of grading and clearing is the
most effective means of reducing sediment yield. This approach not only
maintains some site vegetative cover but also minimizes the temporary
and permanent alteration of the natural hydrology of the site and the
receiving waters, thereby reducing the susceptibility of the receiving
waters to long-term changes in channel incision and expansion which
affects the basin's sediment regime. Short term reductions in sediment
yield can also be accomplished by phasing construction so that only a
portion of the site is disturbed at a time. Another effective approach
is to schedule clearing and grading events to reduce the probability
that bare soils will be exposed to rainfall. Many areas of the country
have defined times during the year when the majority of rainfall (and
hence erosion) occurs. By scheduling major earth disturbing activities
outside of the rainy season, erosion can be significantly reduced.
    Managing stormwater flows on the site can be highly effective at
reducing erosion. Typical practices include actively managing off-site
and on-site stormwater using diversion berms, conveyance channels and
slope drains to avoid stormwater contact with disturbed areas. In
addition, stormwater should be managed using energy dissipation
approaches to prevent high runoff velocities and concentrated flows
that are erosive. Vegetative filter strips are often considered as
sediment controls, but they can also be quite effective at dissipating
energy and reducing the velocity (and thus erosive power) of
stormwater. Stormwater that is directed to vegetated areas can
infiltrate, thus reducing or even eliminating the amount of stormwater
discharged from a site, particularly for smaller storm events.
    After land has been disturbed and construction activity has ceased
on any portion of the site, exposed soils should

be covered and stabilized immediately. Simply providing some sort of
soil cover on these areas can significantly reduce erosion rates, often
by an order of magnitude or more. Vegetative stabilization using annual
grasses is a common practice used to control erosion. Physical barriers
such as geotextiles, straw, rolled erosion control products and mulch
and compost are other common methods of controlling erosion. Polymers
(such as PAM) and soil tackifiers are also commonly used. These
materials and methods are intended to reduce erosion where soil
particles can be initially dislodged on a C&D site, either from
rainfall, snow melt or up-slope runoff.
    The effectiveness of erosion control measures is dependent on
periodic inspection and identification and correction of deficiencies
(e.g., after each storm event). Erosion control measures alone will not
eliminate the mobilization of soil particles and such controls must
often be used in conjunction with sediment control measures.

C. Sediment Control Measures

    Despite the proper use of erosion control measures, some sediment
detachment and movement is inevitable. Sediment control measures are
used to control and trap sediment that is entrained in stormwater
runoff. Typical sediment controls include perimeter controls such as
silt fences constructed with filter fabric and compost filter berms.
Trapping devices such as sediment traps and basins, inlet protectors
and check dams are examples of in-line sediment controls. Sediment
traps and basins are commonly used approaches for settling out sediment
eroded from small and large disturbed areas. Their performance can be
enhanced using baffles and skimmers, and additional removal can be
accomplished by directing trap or basin discharges to a sand filter or
to a vegetated area. Basin and trap performance can also be enhanced by
using chemically-enhanced settling (e.g., polymer or flocculant
addition). Typical chemicals used on construction sites include
polyacrylamide (or PAM), chitosan, alum, polyaluminum chloride and
gypsum. Polymers or flocculants are available in either liquid or solid
form, and can be introduced at several points in the treatment train in
order to increase sediment removal. Liquid chemicals can be introduced
via a metering pump in a channel upstream of a basin, or can be sprayed
onto the surface of a basin. Rainfall-driven systems can also be used
to introduce liquid forms of chemicals into channels or basins. This
configuration allows for operation on nights or weekends when
construction personnel may not be present on-site.
    Conveyances are often used to channelize and manage stormwater on
construction sites, and check dams are often placed in channels to
control flow velocities and to remove sediment through settling and
filtration. Sediment removal by check dams can be enhanced by applying
polymer to the check dam, or by placing a polymer enclosed in a
permeable material, such as a gel sock, or solid forms sometimes
referred to as a floc-block, in the channel. Floc-blocks and gel socks
are effective when placed in channels just prior to a basin, a check
dam or other structure or conveyance, where the water velocity will be
slowed allowing the turbidity, sediment and other pollutants, along
with the polymer, to settle out.
    Sediment removal can be further enhanced by directing discharges
from basins and channels, or by directing discharges through silt
fences or filter berms into vegetation or other buffers between the
site and surface waters to promote filtration and infiltration. Also,
stormwater in basins or other impoundments can be dispersed to
vegetated areas using spray or drip irrigation systems, allowing for
filtration and infiltration.
    Active treatment processes such as electrocoagulation and
filtration can also be used to increase sediment removal.
Electrocoagulation uses an electrical charge to destabilize particles,
allowing removal by settling or filtration. Filtration can be
accomplished by directing stormwater to a sand filter bed, or by
pumping water through vessels filled with sand or other media. Tube
settlers and weir tanks can also be utilized to aid in sediment
removal. When discharges from sediment controls or active treatment
processes are directed to vegetated areas and stormwater is dispersed
and allowed to infiltrate, the amount of stormwater discharged from the
site can be reduced, and in some cases the discharge can be eliminated.
    More detailed descriptions of sediment and erosion control
measures, use of polymers and flocculants and active treatment
processes can be found in the Development Document.

D. Other Construction and Development Site Management Practices

    Construction activity generates a variety of wastes and wastewater,
including concrete truck rinsate, construction and demolition waste,
municipal solid waste (MSW), trash, and other pollutants. Construction
materials and chemicals should be handled, stored and disposed of
properly to avoid contamination of runoff that is discharged from the
site. While mobilization by stormwater is one mechanism by which these
wastes may be discharged from C&D sites, pollutants may also be
discharged if wastes or wastewaters are dumped into streams or storm
drains. Pollutants, trash and debris may also be carried away by wind.
Control of these wastes can be accomplished using a variety of
techniques.
    Site planning, sequencing of land-disturbing activities and phasing
of construction activities are also important management practices.
Limiting the amount of land disturbed at one time, as well as during
the entire construction project, are perhaps some of the most effective
practices to reduce the amount of sediment, turbidity and other
pollutants in discharges. The longer exposed soil areas are left
unprotected, the greater the chance of rainfall-induced erosion. Proper
planning such that soil stabilization activities can occur in quick
succession after grading activities have been completed on a portion of
a site can greatly reduce the amount of sediment and turbidity
discharged. In addition, limiting the amount of land that is ``opened
up'' at one time to the minimum amount that is needed, as well as
limiting soil compaction and retaining natural vegetation on the site,
can greatly reduce erosion rates and help maintain the natural
hydrology. Also, grading of the site to direct discharges to vegetated
areas and buffers that have the capacity to infiltrate runoff can
reduce the volumes of stormwater requiring management in sediment
controls.

E. Performance Data for Passive Treatment Approaches

    Passive treatment systems (PTS), as described in this notice,
include a variety of practices that rely on settling and filtration to
remove sediment, turbidity and other pollutants. Where necessary, PTS
includes the use of polymers or other flocculants. Data in the
literature indicate that PTS are able to provide a high level of