City of Waltham

Stormwater runoff is one of the most significant sources of pollution according to the U.S. Environmental Protection Agency. Surface runoff is able to capture pollutants and debris accumulated on street surfaces and carries this material to the nearest drainage catch basin. Catch basins are the main inlets to the stormwater collection system, which is also comprised of miles of underground pipes and manholes that convey stormwater to the outfall, which usually discharges into a waterbody such as a pond, brook, or river.

Proper management of stormwater is of great importance in order to minimize the entry of pollutants to the storm system and ultimately protect the integrity of our water resources. Stormwater discharges from the City of Waltham, like any other municipality with a dedicated storm water system, are regulated by the EPA’s National Pollutant Discharge Elimination System (NPDES). This system is implemented via a discharge permit that describes the minimum management activities the City must perform in order to improve the quality of its stormwater discharges. Management activities by the City of Waltham are divided in six categories (or minimum control measures) and described in periodic reports submitted to EPA. These minimum control measures are summarized below:

1. Public Education and Outreach:

Waltham’s residents play a very important role in stormwater management. Individual activities and behaviors may have a negative impact on the receiving waters. Trash, paint, solvent or pet-waste disposal; lawn-chemical application; and car washing or maintenance are just some examples of potentially polluting activities when not performed properly.

2. Public Involvement and Participation:

Stormwater management is much more effective in reducing pollution if the affected community is fully involved. Participation, partnership, and combined efforts through community groups working towards the same goal is one of the most powerful tools available to the City. Public involvement is meant to help spread the message on preventing stormwater pollution, to undertake group activities that highlight storm drain pollution, and contribute volunteer community actions to restore and protect local water resources.

3. Illicit Discharge Detection and Elimination (IDDE) Program.

An illicit discharge is usually considered as any discharge into the storm drain system that is not composed entirely of stormwater. Illicit discharges are a problem because, unlike wastewater which flows to a wastewater treatment plant, stormwater generally flows directly into waterways without any additional treatment. Illicit discharges often include pathogens, nutrients, surfactants, and other pollutants. Examples of common sources of illicit discharges are houses with sanitary fixtures connected to the storm drain instead of the sewer, sanitary sewer overflows during severe storm events, washing vehicles in the street, not cleaning up pet waste in public streets and sidewalks, or worse yet, dumping pet-waste directly into catch basins. Runoff from overly fertilized lawn areas also contributes nutrients to the receiving waterways which can generate ecological problems.

4. Construction Site Stormwater Runoff Control

Land disturbances due to construction have a great potential of generating sediment laden runoff which could easily reach the receiving water bodies and have very detrimental impacts on aquatic fauna and recreational water uses. Sediment in waterbodies from construction sites can reduce the amount of sunlight reaching aquatic plants, clog fish gills, smother aquatic habitat and spawning areas, and impede navigation.

The City of Waltham currently regulates stormwater management in construction sites through its Stormwater Ordinance to make sure adequate protection measures are being implemented. Developers and contractors must follow project-specific erosion and runoff control measures in order to avoid damage to the stormwater collection system, neighboring property and roads, or waterbodies.

5. Post-Construction Stormwater Management

Stormwater management does not end when construction ends as new developments or redevelopments may add new flows to the municipal stormwater collection system. Low Impact Development, which enhances stormwater infiltration, as well as adequate operation and maintenance of privately owned infrastructure, is key to meeting long-term targeted water quality standards. In order to guarantee proper post-construction stormwater management, the City of Waltham currently requires surface runoff be treated on-site via infiltration or detention practices whenever possible.

6. Pollution Prevention/Good Housekeeping for Municipal Operations

Municipalities perform numerous activities that may pose a threat to water quality if standard procedures are not implemented to prevent pollutants from entering the storm system. These activities include winter road maintenance, minor road repairs and other infrastructure work, automobile fleet maintenance, landscaping and park maintenance, as well as building maintenance.

Municipalities also conduct activities that remove some pollutants when performed properly. The City of Waltham performs periodic street sweeping of its streets and performs other maintenance and operation activities such as catch basin or drain cleaning on a regular basis. The City of Waltham has also developed Storm Water Pollution Prevention Plans (SWPPP) for areas where de-icing materials are being stored in stockpiles.