[Code of Federal Regulations]
[Title 40, Volume 21]
[Revised as of July 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR123.35]

[Page 254-256]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 123_STATE PROGRAM REQUIREMENTS--Table of Contents
 
                   Subpart B_State Program Submissions
 
Sec.  123.35  As the NPDES Permitting Authority for regulated small MS4s, what is my role?

    (a) You must comply with the requirements for all NPDES permitting 
authorities under Parts 122, 123, 124, and 125 of this chapter. (This 
section is meant only to supplement those requirements and discuss 
specific issues related to the small MS4 storm water program.)
    (b) You must develop a process, as well as criteria, to designate 
small MS4s other than those described in Sec.  122.32(a)(1) of this 
chapter, as regulated small MS4s to be covered under the NPDES storm 
water discharge control program. This process must include the authority 
to designate a small MS4 waived under paragraph (d) of this section if 
circumstances change. EPA may make designations under this section if a 
State or Tribe fails to comply with the requirements listed in this 
paragraph. In making designations of small MS4s, you must:
    (1)(i) Develop criteria to evaluate whether a storm water discharge 
results in or has the potential to result in exceedances of water 
quality standards, including impairment of designated uses, or other 
significant water quality impacts, including habitat and biological 
impacts.
    (ii) Guidance: For determining other significant water quality 
impacts, EPA recommends a balanced consideration of the following 
designation criteria on a watershed or other local basis: discharge to 
sensitive waters, high growth or growth potential, high population 
density, contiguity to an urbanized area, significant contributor of 
pollutants to waters of the United States, and ineffective protection of 
water quality by other programs;
    (2) Apply such criteria, at a minimum, to any small MS4 located 
outside of an urbanized area serving a jurisdiction with a population 
density of at least 1,000 people per square mile and a population of at 
least 10,000;
    (3) Designate any small MS4 that meets your criteria by December 9, 
2002. You may wait until December 8, 2004 to apply the designation 
criteria on a watershed basis if you have developed a comprehensive 
watershed plan. You may apply these criteria to make additional 
designations at any time, as appropriate; and
    (4) Designate any small MS4 that contributes substantially to the 
pollutant loadings of a physically interconnected municipal separate 
storm sewer that is regulated by the NPDES storm water program.
    (c) You must make a final determination within 180 days from receipt 
of a petition under Sec.  122.26(f) of this chapter (or analogous State 
or Tribal law). If you do not do so within that time period, EPA may 
make a determination on the petition.
    (d) You must issue permits consistent with Sec. Sec.  122.32 through 
122.35 of this chapter to all regulated small MS4s. You may waive or 
phase in the requirements otherwise applicable to regulated small MS4s, 
as defined in Sec.  122.32(a)(1) of this chapter, under the following 
circumstances:
    (1) You may waive permit coverage for each small MS4s in 
jurisdictions with a population under 1,000 within the urbanized area 
where all of the following criteria have been met:
    (i) Its discharges are not contributing substantially to the 
pollutant loadings

[[Page 255]]

of a physically interconnected regulated MS4 (see paragraph (b)(4) of 
this section); and
    (ii) If the small MS4 discharges any pollutant(s) that have been 
identified as a cause of impairment of any water body to which it 
discharges, storm water controls are not needed based on wasteload 
allocations that are part of an EPA approved or established ``total 
maximum daily load'' (TMDL) that address the pollutant(s) of concern.
    (2) You may waive permit coverage for each small MS4 in 
jurisdictions with a population under 10,000 where all of the following 
criteria have been met:
    (i) You have evaluated all waters of the U.S., including small 
streams, tributaries, lakes, and ponds, that receive a discharge from 
the MS4 eligible for such a waiver.
    (ii) For all such waters, you have determined that storm water 
controls are not needed based on wasteload allocations that are part of 
an EPA approved or established TMDL that addresses the pollutant(s) of 
concern or, if a TMDL has not been developed or approved, an equivalent 
analysis that determines sources and allocations for the pollutant(s) of 
concern.
    (iii) For the purpose of paragraph (d)(2)(ii) of this section, the 
pollutant(s) of concern include biochemical oxygen demand (BOD), 
sediment or a parameter that addresses sediment (such as total suspended 
solids, turbidity or siltation), pathogens, oil and grease, and any 
pollutant that has been identified as a cause of impairment of any water 
body that will receive a discharge from the MS4.
    (iv) You have determined that current and future discharges from the 
MS4 do not have the potential to result in exceedances of water quality 
standards, including impairment of designated uses, or other significant 
water quality impacts, including habitat and biological impacts.
    (v) Guidance: To help determine other significant water quality 
impacts, EPA recommends a balanced consideration of the following 
criteria on a watershed or other local basis: discharge to sensitive 
waters, high growth or growth potential, high population or commercial 
density, significant contributor of pollutants to waters of the United 
States, and ineffective protection of water quality by other programs.
    (3) You may phase in permit coverage for small MS4s serving 
jurisdictions with a population under 10,000 on a schedule consistent 
with a State watershed permitting approach. Under this approach, you 
must develop and implement a schedule to phase in permit coverage for 
approximately 20 percent annually of all small MS4s that qualify for 
such phased-in coverage. Under this option, all regulated small MS4s are 
required to have coverage under an NPDES permit by no later than March 
8, 2007. Your schedule for phasing in permit coverage for small MS4s 
must be approved by the Regional Administrator no later than December 
10, 2001.
    (4) If you choose to phase in permit coverage for small MS4s in 
jurisdictions with a population under 10,000, in accordance with 
paragraph (d)(3) of this section, you may also provide waivers in 
accordance with paragraphs (d)(1) and (d)(2) of this section pursuant to 
your approved schedule.
    (5) If you do not have an approved schedule for phasing in permit 
coverage, you must make a determination whether to issue an NPDES permit 
or allow a waiver in accordance with paragraph (d)(1) or (d)(2) of this 
section, for each eligible MS4 by December 9, 2002.
    (6) You must periodically review any waivers granted in accordance 
with paragraph (d)(2) of this section to determine whether any of the 
information required for granting the waiver has changed. At a minimum, 
you must conduct such a review once every five years. In addition, you 
must consider any petition to review any waiver when the petitioner 
provides evidence that the information required for granting the waiver 
has substantially changed.
    (e) You must specify a time period of up to 5 years from the date of 
permit issuance for operators of regulated small MS4s to fully develop 
and implement their storm water program.
    (f) You must include the requirements in Sec. Sec.  122.33 through 
122.35 of this chapter in any permit issued for regulated small MS4s or 
develop permit limits based on a permit application

[[Page 256]]

submitted by a regulated small MS4. (You may include conditions in a 
regulated small MS4 NPDES permit that direct the MS4 to follow an 
existing qualifying local program's requirements, as a way of complying 
with some or all of the requirements in Sec.  122.34(b) of this chapter. 
See Sec.  122.34(c) of this chapter. Qualifying local, State or Tribal 
program requirements must impose, at a minimum, the relevant 
requirements of Sec.  122.34(b) of this chapter.)
    (g) If you issue a general permit to authorize storm water 
discharges from small MS4s, you must make available a menu of BMPs to 
assist regulated small MS4s in the design and implementation of 
municipal storm water management programs to implement the minimum 
measures specified in Sec.  122.34(b) of this chapter. EPA plans to 
develop a menu of BMPs that will apply in each State or Tribe that has 
not developed its own menu. Regardless of whether a menu of BMPs has 
been developed by EPA, EPA encourages State and Tribal permitting 
authorities to develop a menu of BMPs that is appropriate for local 
conditions. EPA also intends to provide guidance on developing BMPs and 
measurable goals and modify, update, and supplement such guidance based 
on the assessments of the NPDES MS4 storm water program and research to 
be conducted over the next thirteen years.
    (h)(1) You must incorporate any additional measures necessary to 
ensure effective implementation of your State or Tribal storm water 
program for regulated small MS4s.
    (2) Guidance: EPA recommends consideration of the following:
    (i) You are encouraged to use a general permit for regulated small 
MS4s;
    (ii) To the extent that your State or Tribe administers a dedicated 
funding source, you should play an active role in providing financial 
assistance to operators of regulated small MS4s;
    (iii) You should support local programs by providing technical and 
programmatic assistance, conducting research projects, performing 
watershed monitoring, and providing adequate legal authority at the 
local level;
    (iv) You are encouraged to coordinate and utilize the data collected 
under several programs including water quality management programs, TMDL 
programs, and water quality monitoring programs;
    (v) Where appropriate, you may recognize existing responsibilities 
among governmental entities for the control measures in an NPDES small 
MS4 permit (see Sec.  122.35(b) of this chapter); and
    (vi) You are encouraged to provide a brief (e.g., two page) 
reporting format to facilitate compiling and analyzing data from 
submitted reports under Sec.  122.34(g)(3) of this chapter. EPA intends 
to develop a model form for this purpose.

[64 FR 68850, Dec. 8, 1999]