Illicit Discharge & Pollution Control

When stormwater professionals encounter an unexplained discharge, a suspicious pipe, or a drainage system that does not behave as expected, one of the most effective investigative tools available is dye testing. Used by municipalities, engineers, environmental consultants, utility operators, and reg…

When most people think about stormwater pollution, they think of sediment, nutrients, oils, trash, or road salt. However, heat itself can be a pollutant. Thermal pollution occurs when stormwater runoff becomes significantly warmer than the natural receiving waters it eventually enters. Elevated wate…

Most storm drain inlets quietly collect and convey runoff without attracting much attention from the public. To many residents, a storm drain is simply another opening in the curb or grate in the pavement. What many people do not realize, however, is that storm drains in most municipalities discharg…

Stormwater runoff can cause fish kills through a combination of physical, chemical, and biological mechanisms that alter aquatic environments beyond the tolerance limits of fish and other aquatic organisms. These impacts are often rapid, episodic, and closely tied to precipitation events, especially…

Understanding Natural vs. Problematic Foam in Streams, Channels, and Lakes If you spend enough time around streams, roadside ditches, or lakes, you will eventually notice patches of foam collecting along the edges or drifting in slow-moving water. For many people, the immediate assumption is that th…

Municipal governments are often viewed as stewards of water quality, yet many of their routine, necessary operations can unintentionally contribute pollutants to the stormwater system. Unlike wastewater, which is treated before discharge, stormwater typically flows untreated into nearby streams, riv…

Dry weather outfall screening is one of the most effective and defensible tools available to municipal stormwater programs for identifying illicit discharges. Under MS4 permit requirements associated with the Clean Water Act and the NPDES stormwater program, municipalities are required to implement …

Lake George in upstate New York is often called the “Queen of American Lakes” because of its exceptional clarity and scenic setting in the Adirondack Mountains. For generations, residents and visitors have prized its transparent waters, vibrant fisheries, and tourism economy. Yet in rece…

When crews encounter contaminated sediments during routine work, or when a concerned homeowner reports a suspicious odor or unusual discharge, the situation calls for immediate but steady action. Stormwater systems often collect materials from a wide range of sources, and although many sediments are…

The Salton Sea is one of California’s most unusual and tragic landscapes, a place shaped by accident, transformed by ambition, and ultimately pushed toward collapse by the very forces that sustained it for decades. Its story is a long arc of creation, prosperity, decline, and ongoing struggle,…

A brownfield is real property whose reuse or redevelopment is complicated by the presence or potential presence of a hazardous substance, pollutant, or contaminant. Congress added this definition to the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), recognizing that l…

Stormwater runoff is one of the leading causes of water pollution in the United States. As rainfall or snowmelt flows over impervious surfaces such as roads, parking lots, and rooftops, it collects a wide array of pollutants that are carried into local waterways through storm drain systems. Understa…