The Raritan watershed, commonly known as the Raritan River Basin, covers 1,100 square miles, including the Raritan River, the North and South Branches of the Raritan, and the Millstone River as well as tributaries such as Lawrence Brook and Green Brook. It is the largest river system entirely within New Jersey and supplies (via pumping) the Spruce Run and Round Valley reservoirs. The Raritan River proper forms at the confluence of the North Branch and the South Branch just west of Somerville. It flows 16 miles before slowing in tidewater at New Brunswick. Its estuary extends 14 miles more until the Raritan Bay at South Amboy. 

The US Environmental Protection Agency (EPA) has designated 26 Superfund sites in Middlesex (18 sites) and Somerset (8 sites) Counties.  Many other contaminated sites also drain into the Raritan River.  Current release of toxic chemicals from industrial sources can be obtained from Toxics Release Inventory (TRI) Where You Live | US EPA. 

The latest available data, 2021, indicates that 179 lbs. of the toxic chemicals tracked by the EPA were released into the water in Middlesex County.  In Somerset County water-released toxics totaled 2 lbs.  New Jersey ranks 9 out of 56 states/territories nationwide based on total toxic releases per square mile (rank 1 = highest toxic releases).

Of course, industrial releases are only part of point source pollution, defined by the  U.S. Environmental Protection Agency (EPA) as “any single identifiable source of pollution from which pollutants are discharged, such as a pipe, ditch, ship or factory smokestack.”.  Sewage treatment plants can be a significant source of pollution, especially "nutrient" pollution such as nitrogen and phosphorus.  Landfills that were not well-designed or well-maintained can cause pollution in some areas.

Non-point source pollution results from: "land runoff, precipitation, atmospheric deposition, drainage, seepage or hydrologic modification. NPS pollution, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground waters."  Non-point source pollution may also originate with agricultural and lawn irrigation. 

Of special importance in our area is stormwater runoff, when significant rainfall or snowmelt can't soak into the ground because of numerous impervious surfaces such as roads, parking lots and roofs.  Chemical fertilizers from agriculture and lawn products can enter water sources leading to algal blooms. Sources and Solutions | US EPA  Dangerous algal blooms from excess phosphorus cause water to become unsafe for contact for humans and animals. The Effects | US EPA

In some urban areas, a separate sewer system (not the system carrying human and industrial waste) takes stormwater runoff to local rivers and streams without treatment.  Much worse are single systems which mix stormwater runoff with human and industrial waste and discharge the mixture without treatment when the total volume exceeds the capacity of water treatment plants, a process referred to as a combined-sewer overflow. Perth Amboy in Middlesex County has a combined-sewer system which releases untreated waste in or near Raritan Bay.

Reducing non-point source pollution will require multiple methods, including activities undertaken by government and commercial entities as well as individuals.  Green infrastructure systems slow down, detain, and filter contaminants from storm-water. Runoff can be decreased using porous pavements that allow rainwater to soak into the ground below parking lots, driveways, and paved areas.  Homeowners, businesses, and local municipalities can collect rainwater in rain barrels for later use, plant rain gardens to reduce runoff, and make sure that fertilizer and pesticide use is kept to a minimum.  .  Other examples include vegetated rooftops, buffer strips, forested areas, grassed waterways, constructed wetlands, curb cutouts/bump-outs RiverSmart Washington Curbing Stormwater Pollution | US EPA, and redirected downspouts. Soak Up the Rain: Disconnect / Redirect Downspouts | US EPA

The primary focus of reducing water pollution was for many years on point sources.  The focus is now more comprehensive by also reducing non-point source pollution using improved methods and materials.     

Links to Additional Information 

Educational Resources:

Publications Principles of wetland restoration from EPA

Watershed & Land Management New Jersey Department of Environmental Protection

Watershed Protection Plans New Jersey Water Supply Authority

River-Friendly Resident Online Guidance Materials New Jersey Water Supply Authority

Green Infrastructure in the Raritan Basin (and Beyond)

Organizations:

Raritan Headwaters Association

Raritan Riverkeeper | NY/NJ Baykeeper

Sustainable Raritan River Initiative Rutgers School of Environmental and Biological Sciences

Raritan River Initiatives  Rutgers Center for Urban Policy Research