Background information about stormwater

What is stormwater, and why is it a problem? 

Stormwater 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, compacted areas, and bare soil, and through sloped lawns while picking up a variety of materials on its way. 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. New and existing development typically adds impervious surfaces and, if not properly managed, may alter natural drainage features, increase peak discharge rates and volumes, reduce recharge to wetlands and streams, and increase the discharge of pollutants to wetlands and water bodies.

As it flows, stormwater runoff collects and transports pollutants to surface waters. Although the amount of pollutants from a single residential, commercial, industrial or construction site may seem unimportant, the combined concentrations of contaminants threaten our lakes, rivers, wetlands and other water bodies. Pollution conveyed by stormwater degrades the quality of drinking water, damages fisheries and habitat of plants and animals that depend on clean water for survival. Pollutants carried by stormwater can also affect recreational uses of water bodies by making them unsafe for wading, swimming, boating and fishing. Stormwater runoff represents the single largest source responsible for water quality impairments in the Commonwealth’s rivers, lakes, ponds, and marine waters. According to an inventory conducted by the United States Environmental Protection Agency (EPA), half of the impaired waterways are affected by urban/suburban and construction sources of stormwater runoff. The Neponset river and other Milton water bodies are impaired by several contaminants, including phosphorus and polychlorinated biphenyls (PCBs).

National Pollutant Discharge Elimination System (NPDES)

In 1972 the US EPA created the Clean Water Act (CWA), which helps address water pollution by regulating point sources that discharge pollutants to waters of the United States. An offshoot of the CWA was the National Pollution Discharge Elimination System program (NPDES).

The NPDES program, in place since 1990, regulates discharges from municipal separate storm sewer systems (MS4s), construction activities, industrial activities, and those designated by EPA due to water quality impacts. At the onset of the program only large cities were regulated under NPDES. In 2003 NPDES jurisdiction was widened to include all communities (except the very smallest and most rural) across all of the USA. This expanded jurisdiction is known as NPDES Phase II, and Milton became included in the NPDES jurisdiction. The NPDES permit for Massachusetts was set to expire after five years from the effective date (2003-2008). Ever since 2008, EPA has issued annual extensions to the permit so that they, and all states, could work out the conditions and requirements of a proposed broader and stricter new permit. Finally, in 2016 EPA issued the new permit to Massachusetts, which affects all communities, including the Town of Milton. The new permit, which is issued jointly by EPA and the Massachusetts Department of Environmental Protection, will become effective in 2018. For more general information on NPDES from EPA, click here.

How does NPDES affect Milton?

Milton has been in compliance with the EPA permit since it was first issued in 2003. Complying with the first permit has been costly. However, the expanded EPA requirements under the new permit are very significant and extremely costly. It will cost more than $700,000 for Milton to fully comply with the first year requirements of the new EPA permit. Some requirements of the new permit include a complete inventory of sewer discharges in Milton, new regulations for construction and redevelopment sites, pollution prevention, and public outreach components.

Milton, like many towns across the nation, has wrestled with the question of how to pay for the cost of NPDES compliance, as the federal mandate is unfunded. However, Milton’s efforts have been far ahead of other community’s efforts by addressing the cost question for over three years now. A pilot study was commissioned allowing Milton to develop and understand what the cost implications of the new permit would be and to identify and consider several funding options.

The Stormwater Utility in Milton

During the fall of 2015 the Board of Selectmen publically embarked upon a solution to the stormwater funding issue. A series of several public hearings were conducted where the NPDES affordability issue was discussed. These hearings afforded citizens the opportunity to learn about the issue, ask questions, and to offer comments. The result of these hearings was a decision that a new Stormwater Utility should be created, preferably under a dedicated enterprise system. The new utility could bill stormwater fees, make collections, and segregate funds such that those funds could ONLY be used for stormwater purposes. In February, 2016 Town Meeting debated and approved the creation of a new Stormwater Utility Enterprise.

During the spring and early summer months of 2016, the Board of Selectmen embarked upon a second series of several public hearings. These hearings were conducted regarding development of new stormwater regulations. These hearing again afforded citizens several opportunities to offer comments and debate the issue. However, this time the discussions during the hearings were specific to develop, understand, and debate the very many options that are available to be used in developing a stormwater fee.

Of all of the options available, and as a matter of providing the greatest degree of fairness and equity to all fee payers, the Board of Selectmen elected to base the stormwater fee calculation on a “per square-foot of impervious surface” basis. The selectmen also chose to use a four-tier system that would set a fixed annual stormwater fee for each of the four ranges of impervious area for single-family properties. The annual stormwater fee for all other property types would be based upon a calculation of the property’s impervious area. For more details on this calculation, see How is My Stormwater Fee Generated?.