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EXPLAINER | Stormwater runoff
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Stormwater runoff

As of 2022, nearly two-thirds of Pennsylvania lakes are polluted. 

This year marks the 50th anniversary of the United States government’s revival of the Clean Water Act. The legislation is meant to regulate water pollution to ensure the safety of drinking water, economic and recreational developments, and aquatic life. 

But Pennsylvania is still struggling to address its impaired waters.

Research has shown with the help of climate change and a slew of other human-induced factors, polluted runoff has contributed immensely to the widespread deterioration of Pennsylvania’s bodies of water, especially in the Chesapeake Bay.

The commonwealth makes up 35% of the six-state-wide Chesapeake Bay watershed. That means that most of Pennsylvania’s stormwater runoff drains into the Chesapeake Bay.

Associated Press

Pennsylvania’s dairy industry has been struggling for several years.

On its way downstream, runoff mixes into freshwater rivers and streams like the Susquehanna River, which is the Bay’s largest tributary. Oftentimes, that runoff is contaminated with chemical fertilizers and littered with plastic debris. The Environmental Protection Agency calls polluted runoff “one of the greatest threats to clean water in the U.S.”

It’s important to have open soil to soak up the rainwater, filter out unwanted chemicals and debris, and allow water to travel back through plant roots to be released into the air.

This means that impermeable surfaces – those that don’t allow water and good nutrients to soak into the soil – must not be placed in key drainage areas. Drainage occurs within a watershed, which is the large area of land that funnels into a common waterway, like the Chesapeake Bay. Impermeable surfaces instead divert contaminated water down roads, into sewage systems, and eventually into our water.

But how does our water become contaminated in the first place?

First, we’ll need to understand the processes at work.

After the Storm

Every time it rains or snows, water seeps into the soil, nourishes plants, and recharges our river basins: huge depots where we store all of the water that we treat for drinking. Soil is a natural filter for unwanted chemicals and larger pollutants like paper and plastic waste. Filtered water can then absorb into plant roots via osmosis and begin the process of transpiration.

During transpiration, water cruises upward through the plant stem to replenish its energy reserves. After, it evaporates through pores in the plant’s leaves called stomata. Evaporated water is left to mix with the air and absorb into the clouds. 

Water also evaporates from larger bodies of water, like rivers and oceans, into the sky and the clouds.

The combination of precipitation, evaporation, and transpiration makes up the water cycle. 

Madison Goldberg / StateImpact Pennsylvania

Coneflowers and trees grow in the rain garden on the corner of Bailey and North 13th streets in Summit Terrace. “These were little babies when we were doing this,” said Rafiyqa Muhammad, who helped create the garden. “Everything has grown.”

Many cities, however, install impermeable surfaces like concrete and asphalt above stripped ground. As a result, water meant to soak into the soil slips its way down city streets, bringing dirt, chemicals, and trash with it. Stormwater drains capture that polluted water and transport it through stormwater sewage systems that empty out directly into rivers and streams.

Contaminants found in stormwater

General health risks related to someone’s exposure to polluted water can include respiratory infections, diarrheal diseases, and malnutrition. More information can be found below and here.

Chemicals/bacteria: When farmers and homeowners use fertilizers to promote the growth of their crops and grasses, and when we use pesticides to kill bugs and weeds in our backyards and ranches, we’re leaving our water vulnerable. Stormwater that follows the curve of the watershed collects these chemicals in puddles, where they eventually flow downhill and into stormwater drains. Chemicals like these can cause dangerously large algal blooms in any body of water, which can suffocate fish and cause rashes and stomach illnesses. Bacteria present in recreational water in lakes, rivers, and pools can also easily infect the body. Leptospirosis (otherwise known as mud fever or Weil’s disease), typhoid fever, cholera, and urinary tract infections are just a few examples of bacterial infections of major risk.

Cleaning supplies/household items: Detergents and bleach used to clean cars on sidewalks outside homes don’t just end up flowing down your driveway – they enter storm drains and contaminate water downstream. Paint from small house projects and large construction projects, as well as other construction debris, are also hazardous to our stormwater. Chemicals in these products can kill off freshwater fish and produce Persistent Organic Pollutants, like the pesticide DDT, that take years to decompose.

Garbage waste: Cigarette butts, Styrofoam, plastic bottles, candy wrappers, straws–anything littered onto our streets can be swept into storm drains to eventually pollute our water supply. Plastic in the water can look a lot like food to fish, so many get caught in the trap of eating then choking on our trash. Another, long-term example of the danger of garbage in water is the microplastics epidemic, which has recently been picking up steam because researchers have found microplastics in fresh snow in Antarctica.

Catalina Jaramillo / WHYY

Stormwater drains in Philadelphia have traps to capture trash, but smaller pieces of plastic can get through all the way to the river.

Bodily waste from humans/animals: Bacteria from human and animal waste (including waste from your pets) that isn’t treated properly can contaminate runoff. Waste like this contains extremely high levels of phosphorus and nitrogen, which have been shown to be toxic to marine life and notoriously difficult to remove.

Oil: Used motor oil from vehicle leaks, inappropriately disposed oil containers, and oil extractors and refineries can all contribute to oil’s role in contaminating stormwater runoff. “The EPA estimates that American households improperly dump about 193 million gallons of used oil every year, or roughly the equivalent of 17 Exxon Valdez oil spills,” says the EPA’s Pacific Southwest Stormwater Program page.

The problem isn’t the runoff–it’s the pollution

Stormwater is vital to the maintenance of the water cycle. Clean water that flows through stormwater sewage systems and empties out into larger bodies of water can then replenish the water cycle. The goal of stormwater pollution prevention is to direct rainwater and melted snow into storm drains as quickly as possible – before it can be contaminated, hopefully nipping the problem in the bud.

The EPA gives us a few tips on how to combat water pollution:

  • Use fertilizers sparingly, and sweep up driveways, sidewalks, and gutters.
  • Never dump anything down storm drains or in streams.
  • Vegetate bare spots in your yard.
  • Compost your yard waste.
  • Use least toxic pesticides, follow labels, and learn how to prevent pest problems.
  • Direct downspouts away from paved surfaces; consider a rain garden to capture runoff.
  • Take your car to the car wash instead of washing it in the driveway.
  • Check your car for leaks, and recycle your motor oil.
  • Pick up after your pet.
  • Have your septic tank pumped and the system inspected regularly.

A glance at some community-based solutions

  • Rain Gardens: The Bright Side Baptist Church in Lancaster, Pa., built a rain garden on its property in May 2022. It’s meant to capture rain before it flows down the road and collects pollutants. The congregation planted milkweed, switchgrass, sedge, turtlehead, soft rush, purple coneflower, and blue cardinal flower. Their rain garden has a capacity of more than 320 gallons of water, which can be collected from the church’s roof.
  • Rain Barrels: Every year, high school students at Cedar Cliff High School in Camp Hill construct and sell 50 rain barrels made from reused food bins. Users can collect rainwater from their roofs and use the water for their yards during dry months. Since it began, the program has distributed over 1,500 rain barrels throughout Cumberland County, each saving over 1,000 gallons of water every year.
  • Live Stakes: In 2019, volunteers in Lansdowne and Montgomery creek valleys in Philadelphia planted live branches into soil around their waterways to stabilize streams and avoid erosion. This way, less dirt and chemicals could run into the water as the branches bloomed. Live staking can result in similar vegetative cover to two seasons’ worth of planted shrubs and trees, and it’s a lot less costly.

-Adriana Delagarza, StateImpact Pennsylvania

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