April Showers bring - Stormwater Runoff by Julie Backenkeller

A few weeks ago, Frontline (PBS) aired a 2 hour feature called “Poisoned Waters”. It was an eye opening program that outlined, in excruciating detail, the damage being done to US waterways by pollutants, storm-water runoff, manure from large farming operations, and sprawling development. You can watch it on line, at http://www.pbs.org/wgbh/pages/frontline/poisonedwaters/clean/

One of the things we need to keep in mind here in Janesville, is that most of what runs into our sewers, runs eventually, untreated, into the river or the greenbelt. I never realized this until I read a screened notice on the storm drain up north, stating something like “Do not dump anything in here, this empties directly into the lake.” As with most people, I hadn’t given much thought to what happens to rainwater, after it hits the ground. This is also why the City of Janesville periodically sweeps the streets!

Storm water runoff, created by impervious surfaces (roofs, roads-concrete), is the “leading remaining cause of water-quality problems” in the US, according to the EPA. When it rains, or snow melts, water picks up chemicals we have left behind from vehicles, lawn fertilizers, pet and livestock waste – the list goes on. Jay Manning, Washington Department of Ecology, states that storm-water in his state “picks up on an annual basis, a volume of oil that is equivalent to half of the Prince William Sound spill from Exxon Valdez.”

Development contributes to the problem. When rain falls on farm or forested land, it filters down through the trees and plants, through the soil, and moves slowly through the ground to emerge clean in streams and rivers. If these areas are developed, rainwater lands on pavement or rooftops, moves quickly across the impermeable surface, resulting in possible flooding, damage to habitat in and around waterways and damage for people downstream. Urbanization also increases the variety and amount of pollutants transported to receiving waters, according to the EPA.

What types of contaminants are found in stormwater?

According to stormwaterauthority.org, stormwater pollution can be divided into three categories:
Natural — organic material such as leaves, grass clippings and sediment
Chemical — such as detergents, coolant, oil, grease, fertilizer and paint
Litter — such as plastic bags and cigarette
Check out their website at http://www.stormwaterauthority.org/pollutants/default.aspx to learn more.

The newest threat is pavement sealcoats. They may make pavement look nice, but they contain polyaromatic hydrocarbons (PAHs), that wash off into stormwater, and into our waterways. PAHs are highly carcinogenic, and do not break down easily, thus will remain in the environment for decades.

What can we do? The EPA offers a list of household do’s and don’ts to reduce your personal contribution, and fact sheets about sources of runoff, and ideas for low impact development. http://www.epa.gov/weatherchannel/stormwater.html

Sooner or later, stormwater ends up in someone’s drinking water. Emerging contaminants post a threat to drinking water because older filtering systems are not designed to catch them. Technology for screening and detecting contaminants in the environment can’t keep up with new chemicals manufactured by companies.

Protecting Wisconsin’s waterways is the subject of this in depth study by the WISPIRG Foundation
http://act.americanrivers.org/site/DocServer/Protecting_Wisconsin_s_Water.pdf?docID=5381

email: rockenvironmentalnetwork@charter.net