The U.S. Environmental Protection Agency (EPA) is initiating a peer review of draft scientific modeling approaches to inform EPA’s evaluation of...
In December of 1999, the United States Environmental
Protection Agency (EPA) published the National Pollutant Discharge Elimination
System (NPDES) Phase II Stormwater rule in the Federal Register. The issuance
of the rule started a clock that has had municipalities, and stormwater
professionals working to understand and evaluate its implications.
Applications for Phase II permit coverage are due by March
10, 2003. The amount of preliminary work to get permit coverage can be
extensive, and regulated municipalities should be in the process of determining
what their particular permitting authority?s requirements are and what
actions are needed to be in compliance when the Phase II deadline arrives.
The Phase II rule is an extension of the NPDES Stormwater
program. The Phase I Stormwater Rule was issued in 1990 and covered medium and
large municipal separate storm sewer systems (MS4s). These include cities or
jurisdictional entities serving populations over 100,000. In addition,
operators of construction activities disturbing more than five acres and 11
categories of industrial activities were required to obtain separate permit
coverage under Phase I.
Phase II will extend NPDES Stormwater permit requirements to
small MS4s and construction activities disturbing more than one acre. Unlike
the numeric requirements set in Phase I that had extensive monitoring demands,
the Phase II rule has a narrative approach. Those municipalities regulated
under the general permit requirements of Phase II will not have to establish
pollutant characterization of stormwater quality by conducting analytical testing.
The implementation of Best Management Practices (BMPs) and associated
measurable goals will be sufficient to meet compliance with the six minimum
measurement requirements of Phase II.
The Phase II Stormwater rule automatically will cover
operators of MS4s that are located within an "urbanized area" with
a total population of 50,000 or more and a density of at least 1,000 persons
per square mile. These regulated areas include all jurisdictions within the
defined area regardless of individual population numbers and are based on
official 2000 U.S. census data. Municipalities that are being added to the list
of "automatic" coverage as a result of the 2000 census still will
have to comply by March 10, 2003. Therefore, there are many municipalities that
are just learning they will need to apply for permit coverage.
A "municipality" for purposes of the permit is
defined by the rule to include not only what is traditionally thought of as a
municipality (e.g., cities, towns and villages) but also state agencies, counties,
federal installations, military bases and Native American lands. The definition
also includes state-owned or -operated departments of transportation,
universities, school districts, public hospitals and even local drainage, sewer
or water conservation districts that operate separate storm sewer systems. In
addition, the definition of what constitutes a "separate storm sewer
system" includes any method of conveying surface water, including
streets, gutters, ditches, swales or any other manmade structures that in any
way alter natural wet-weather flow. Thus, the impact of the Phase II rule is
Along with the automatically designated MS4s, the Phase II
rule also requires the NPDES Permitting Authority (in most cases, individual
states) to establish criteria for including those MS4s located in population
areas of at least 10,000, if it determines that wet-weather flow discharges
from that municipality have an adverse impact on the quality of receiving
waters. Permitting authorities also have the option of including municipalities
as designated MS4s with populations as low as 1,000 under certain conditions.
Any municipality that becomes a designated MS4 will have 180 days from the date
of designation to obtain permit coverage. These designations are supposed to
occur by December 2002.
Finally, MS4 operators with populations of fewer than 1,000
outside of automatic and designated areas also may need stormwater permits for
discharge if permitting authorities determine that the MS4 is contributing
substantially to pollutant loading of a physically interconnected and regulated
A municipality's individual permit application or
notice of intent for coverage under a general permit must include descriptions
of the BMPs and measurable goals that will be used to meet the following six
Public Education and Outreach. This measure must include a
program designed to educate the public about the impacts of stormwater discharges
on receiving waters and what individuals can do to prevent stormwater
Public Participation and Involvement. This measure must
include a procedure for giving the public an opportunity to actually
participate in both the development and implementation of a stormwater program.
Elicit Discharge Detection and Elimination. Regulated
municipalities must develop a plan with mechanisms designed to locate and
eliminate discharges into storm sewers from sources other than stormwater. This
plan must include a complete map of all outfalls and identification of
locations and sources of any water entering a system.
Construction-Site Runoff Control. Regulated municipalities
must have a regulatory mechanism in place for erosion and sediment control as
well as BMPs for preventing or reducing other pollutants associated with
construction activity. It is important to note that this measure does not
relieve the requirements of a construction-site operator to obtain an
independent NPDES permit for sites larger than one acre. However, the state
permitting authority can specifically reference qualifying local programs in
the NPDES general permit requirements so that the construction operator does
not need to follow two different sets of requirements.
Post-Construction Runoff Controls. Regulated municipalities
must have a program requiring new and redevelopment projects to implement
on-site controls that will reduce pollutant loads in stormwater runoff.
Pollution Prevention and Good Housekeeping. Regulated municipalities
must have an operation and maintenance program to prevent or reduce pollutant
runoff from municipal operations.
While these measures are the minimum required by EPA, the
rule allows for states with NPDES permitting authority to develop permits that
may require more stringent measures to meet water quality requirements. In
addition, municipalities also may develop local stormwater regulations that go
beyond the requirements of Phase II.
The Phase II rule is drafted to encourage development of a
stormwater management control plan that fits local conditions and allows
flexibility by local authorities to meet their individual needs. However, those
MS4s that wait until the last minute are likely to face much higher costs and
possibly more prescriptive requirements that will not take into account local
conditions. Therefore, officials, planners and stormwater professionals who
have not yet started the planning process should do so now.
In addition to the changes noted above for municipal and
construction activities, Phase II also will affect Phase I-regulated industrial
activities. Under Phase II, all industrial activities now will be eligible for
no-exposure waivers instead of only light industries defined in Category 11.
However, all Category 11 industries will need to file waivers or obtain a
permit; under Phase I, Category 11 industries with no exposure did not need to
file these waivers.
Finally, under the Intermodal Surface Transportation and
Efficiency Act (ISTEA) moratorium, municipalities did not need permits for
their industrial activities such as transportation centers. This moratorium
will end on March 10, 2003, and all municipalities then will need additional
NPDES permit coverage for regulated industrial activities.
Since Phase II is a narrative rule that requires the
implementation of BMPs to achieve compliance, selection of the proper mix of
BMPs appropriate for a municipality becomes critical. The Phase II rule
requires that EPA and permitting authorities prepare BMP menus for each minimum
measure to assist MS4s in developing the stormwater management program BMP
"toolbox." These menus will include both structural and
There are a wide range of available BMP options and choosing
the one best for a particular purpose or application depends, in large part on
local conditions. Future articles will give more details on specific BMP types.
A more generalized list is set out below.
Nonstructural BMPs may include
meetings and citizen groups,
cleanups, monitoring programs and ?Adopt-A-Storm Drain? programs,
discharge detection programs,
ordinances and other regulatory mechanisms, including
on non-storm discharges into separate storm sewers,
for control of erosion, sediment and other pollutants on construction sites,
and other site-plan approval processes requiring post construction stormwater
operation and maintenance requirements with regulatory enforcement provisions,
for inspecting and monitoring structural BMPs,
sweeping, catch-basin cleaning and organic yard waste controls,
materials and municipal maintenance activities and schedules, and
and pollution prevention programs.
Structural BMPs may include
BMPs such as constructed wetlands, swales, filter strips and rain gardens,
BMPs (with pretreatment where necessary for groundwater and wellhead
protection) such as basins, trenches, sand filters and porous pavement,
and retention methods for controlling both volume and quality of water flow
into MS4s and receiving waters,
controls such as separators, filtration devices, catch-basin inserts and
and drain grates.
These are just a few examples of BMPs that could be used to
meet Phase II requirements. The rule does not set limits as to which BMPs can
be used. States and regulated municipalities likely will develop their own BMP
requirements, and planners should examine their own state and local
With many proprietary technologies entering the marketplace,
state and local officials and stormwater professionals need to conduct research
to ensure that various claims regarding BMP capabilities are accurate. Various
verification protocols and testing procedures are in place or being developed
to assist decision makers on what specific technologies should be allowed and
for what applications. The EPA through its Environmental Verification Program
(ETV) has developed protocols for testing proprietary claims. There also are
various BMP databases available on the web.
With the Phase II deadline approaching fast, there is a
growing sense of apprehension among impacted municipalities. Yet, while at
first glance the Rule's requirements may seem overwhelming, they are not
that difficult to comply with. Future articles will provide more specifics
about issues such as BMP selection, measurable goals, ordinance development and
other Phase II related issues. The days when stormwater management meant only
"moving the water" are clearly over. However, with careful
planning, municipalities and others affected by the NPDES Phase II Stormwater
regulations will be able to meet the compliance deadlines and requirements
The following individuals helped review this article for
accuracy: Roger Bannerman, Wisconsin DNR; Gary Minton, Resource Planning
Associates; Roger Sutherland, Pacific Water Resources, Inc.; Kelly Cave, Wayne
County Michigan, Department of Environment.