Stormwater Phase II Final Rule

Village of Tarrytown Stormwater Management

We live in a nation that is determined to maintain a healthy and sanitary environment. This includes our nation's bodies of waters. Since the passage of the Clean Water Act (CWA), the quality of our waters has improved dramatically. Despite our progress and accomplishments, 40 percent of surveyed U.S. waterbodies are still contaminated with pollutants and are not up to water quality standards.

One of the central sources of contamination for these bodies of water is polluted stormwater runoff from urban/suburban areas.

What is Stormwater Runoff?

Stormwater runoff is water from rain or melting snow that doesn't soak into the ground but runs off into waterways. It flows from rooftops, over paved areas and bare soil, and through sloped lawns. The runoff from stormwater discharges collects and transports pollutants such as suspended solids, sediments, herbicides, oil and grease, heavy metals, toxins, bacteria, animal waste, salt, pesticides and petroleum hydrocarbons while picking up a variety of materials on its way. Water contamination from such sources results in closed beaches, ban on fishing and fishing areas, beach and shoreline litter, less aesthetic surroundings, unwanted erosion, loss of marine and animal life, and even degradation of drinking water. The quality of runoff is affected by a variety of factors and depends on the season, local meteorology, geography and upon activities which lie in the path of the flow.

What's being done?

Significant improvements have been achieved in controlling pollutants that are discharged from sewage and wastewater treatment plants. Across the nation, attention is being shifted to other sources of pollution such as stormwater runoff. Stormwater management, especially in urban areas, is becoming a necessary step in seeking further reductions in pollution in our waterways and presents new challenges.

Stormwater runoff normally cannot be treated in the same way as accomplished by sewage and wastewater treatment plants. More often than not, end-of-pipe controls are not the best answer for removing pollutants from stormwater runoff. Pollutants in runoff enter our waterways in numerous ways and the best way of control is usually at the pollutant's source. Sometimes, significant improvements can be made by employing best management practices, or "BMPs". Proper storage of chemicals, good housekeeping and just plain paying attention to what's happening during runoff events can lead to relatively inexpensive ways of preventing pollutants from getting into the runoff in the first place and then our waterways.

Urban Runoff/Storm Sewers:

In the natural state, the porous and varied terrain of natural landscapes like forests, wetlands, and grasslands trap rainwater and snowmelt and allow it to slowly filter into the ground. Runoff tends to reach receiving waters gradually. In contrast, nonporous urban landscapes like roads, bridges, parking lots, and buildings don't let runoff slowly percolate into the ground. Water remains above the surface, accumulates, and runs off in large amounts. Cities install storm sewer systems that quickly channel this runoff from roads and other impervious surfaces. Runoff gathers speed once it enters the storm sewer system. When it leaves the system and empties into a stream, large volumes of quickly flowing runoff erode streambanks, damage streamside vegetation, and widen stream channels. In turn, this will result in lower water depths during non-storm periods, higher than normal water levels during wet weather periods, increased sediment loads, and higher water temperatures. Sediment from development and new construction; oil, grease, and toxic chemicals from automobiles; nutrients and pesticides from turf management and gardening; viruses and bacteria from failing septic systems; road salts; and heavy metals are examples of pollutants generated in urban areas. Sediments and solids constitute the largest volume of pollutant loads to receiving waters in urban areas. When runoff enters storm drains, it carries many of these pollutants with it. In older cities, this polluted runoff is often released directly into the water without any treatment. Increased pollutant loads can harm fish and wildlife populations, kill native vegetation, foul drinking water supplies, and make recreational areas unsafe.

To combat this source of pollution the EPA introduced their Stormwater program in 1990 under the Clean Water Act (CWA).

At that time, the program introduced Phase I of its two-phase agenda.

Phase I depends on our country's National Pollutant Discharge Elimination System (NPDES) permit in order to effectively battle polluted runoff from:

  • Large cities and towns (populations of 100,000 or more) with municipal separate storm sewer systems (MS4s).
  • Construction activity disturbing five or more acres of land.
  • Ten categories of industrial activity.

Phase II Requirements

In the December of 1999 the EPA began Phase II Final Rule of the Stormwater program. Phase II Stormwater Management is a federally-mandated program aimed at cleaning up the waterways in the entire country. Phase II expands Phase I to introduce NPDES permits to cover smaller municipal Small Storm Sewer Systems (MS4s) such as Tarrytown located in "urbanized areas" as defined by the Bureau of Census, and all operators of construction sites that disturb one acre or more of land or are part of a larger plan of development.

The communities acknowledged in Phase II must develop and implement a storm water control program involving the following six Minimum Control Measures which will help reduce polluted runoff to greatest amount possible:

Minimum Control Measure 1: Public Outreach and Education on Stormwater Impacts and Program.

Involves informing citizens about the water quality impacts of the polluted stormwater discharges. The measure includes information on steps that a person may take to reduce pollution such as proper maintenance of septic systems, minimizing the use of garden chemicals such as fertilizers, pesticides and herbicides, disposal of household hazardous wastes, and vehicle oils, as well as ways to get involved in the protection measures.

Minimum Control Measure 2: Public Involvement/Participation in Stormwater Program.

The measure includes involving the public in the development and implementation of the storm water management program. The public participation process should reach out to engage all economic and ethnic groups. The program has to identify key individuals and groups affected by the stormwater program, identify the type of input sought and the participation methods the MS4 will employ, identify the name of contact person for the stormwater management program and present the draft annual report to the public.

Minimum Control Measure 3: Illicit Discharge Detection and Elimination.

The MS4 must establish plans to detect and eliminate illicit discharges to the storm sewer system. All the outfalls from the storm sewer systems to surface waters including pipes, road ditches, swales and other stormwater carriers must be mapped and public employees and the community should be informed about the hazards of illegal discharges and improper waste disposal. The plan must address all non-stormwater discharge flows found to be substantial contributors of pollutants, such as water line flushing, irrigation, lawn watering, swimming pool discharges, street washing and foundation drains. Emphasis is placed on the elimination of inappropriate connections to storm drains. Municipalities must locate sources of non-storm water discharges into storm drains and institute appropriate actions for their elimination.

Methods of detecting illegal discharges may include dye tests, smoke tests, random checks of homes, field screening, review of maps and house plans, and notification for self-identification and self-elimination within a given grace period followed by fines if detected by the municipality. The Municipality may need to evaluate its existing codes and ordinances to determine its authority with respect to prohibiting certain connections and discharges, and modify the codes and ordinances to grant it the necessary authority. Illicit discharges can be from a storm drain that has measurable flow during dry weather containing pollutants and/or pathogens. If no pollutants are present, the flow is simply considered discharge. Each illicit discharge has a certain frequency, composition and mode of entry in the storm drain system. Illicit discharges are frequently caused when the sanitary sewage system interacts with the storm drain system. Illicit discharges of other pollutants can be produced by specific source areas such as businesses or industrial operations. Some non-storm water discharges to the MS4 may be allowable, such as discharges resulting from fire fighting activities and air conditioning condensate.

Dry weather flows from the storm drain system may contribute even more pollution than wet weather flow. Detecting and eliminating these illicit discharges is complex. Communities need to systematically characterize their stream, conveyance and storm sewer infrastructure.

Minimum Control Measure 4: Construction Site Stormwater Runoff Control

The operators of regulated MS4s are required to adopt new local laws, amend the existing laws and ordinances, or establish an equivalent regulatory mechanism to reduce pollutants in stormwater runoff from construction activities that disturb one or more acres of land. The measure could include preconstruction review of site plans for storm water runoff controls and regular inspections during construction.

Minimum Control Measure 5: Post-Construction Stormwater Management

The operators of regulated MS4s are required to adopt new local laws, amend the existing laws and ordinances, or establish an equivalent regulatory mechanism either separately or in conjunction with Minimum Measure 4 to reduce pollutants in stormwater runoff after completion of construction. In order to reduce pollutants in post-construction stormwater runoff, construction site operators will need to build permanent stormwater management practices (structural measures) and or establish other (non-structural) measures during land development.

Minimum Control Measure 6: Pollution Prevention/Good Housekeeping

The measure includes improvements to ongoing operations and maintenance (O&M) activities and addresses adequate consideration of water quality concerns. The O&M programs need to be expanded to complement the other five Phase II control measures by adding water quality items to maintenance activities, inspections, pesticide use, catch basin cleanouts, sewer/catch basin repairs, disposals of waste from cleaning storm water systems.

New York State Implementation of Phase II

Under the NPDES storm water program, operators of large, medium and regulated small municipal separate storm sewer systems (MS4s) require authorization to discharge pollutants under an NPDES permit.

Medium and large MS4 operators are required to submit comprehensive permit applications and are issued individual permits. Regulated small MS4 operators have the option of choosing to be covered by an individual permit, a general permit, or a modification of an existing Phase I MS4's individual permit.

To implement the law in the state of New York, the New York State Department of Environmental Conservation has issued two general permits, one for MS4s in urbanized areas and one for construction activities. The permits are part of the State Pollutant Discharge Elimination System (SPDES).

? The SPDES General Permit for Stormwater Discharges from Construction Activity: GP-02-01

? The SPDES General Permit for Stormwater Discharges from Municipal Separate Stormwater Sewer Systems, or MS4s : GP-02-02

The Phase II rule requires regulated MS4s to adopt local laws or other regulatory mechanisms for controlling construction site erosion and post-construction stormwater runoff. In New York State, Stormwater management programs in all regulated MS4s must be fully developed and implemented by January 8, 2008

Village of Tarrytown Implementation of Phase II:

In accordance with the NYSDEC requirements, the Village of Tarrytown prepared and filed the Notice of Intent (NOI) with the NYSDEC on March 5, 2003, to be covered under the Phase II SPDES General Permit GP-02-02 available through the NYSDEC.

The village prepared an initial Storm Water Management Program (SWMP), with an aim to set measurable goals that the village has to implement and enforce in order to comply with the permit requirements. It describes various actions that the village proposes to undertake over a period of five years starting from 2003, to protect the Village's storm water quality and reduce pollutants, until the full implementation of the SWMP (not later than January 8, 2008).

In order to document progress towards achieving the measurable goals identified in the SWMP, the village evaluates its program and submits an annual report with the results to the NYSDEC. The program is currently in its fourth year.

Recently the Village of Tarrytown prepared the Storm Water Management Program Annual Report for the period March 10, 2008 to March 9, 2009, that was presented to the residents of the Village of Tarrytown for public review on May 28, 2009 at 12:00 P.M. at the Village Senior Center. The report illustrates the progress made by the Village towards the Notice of Intent and the Storm Water Management Program (SWMP) submitted by the Village to the NYSDEC in March 2003.

Storm Water Contact Person:

Michael McGarvey
Village Engineer
Village of Tarrytown

To report illicit discharges into storm sewer e-mail, click here.

Relevant Websites for further information on these and other topics to prevent Pollution of Rivers, Streams and Water Bodies: