Pollution gains prove elusive in Delaware
Forty-six years after the first Earth Day raised environmental awareness, regulators, scientists and citizens in Delaware are still struggling to find solutions to water and air pollution issues.
The movement spurred passage of the Clean Air Act and Clean Water Act, and these days, air from smokestacks and water from sewage treatment facilities is cleaner.
Oxygen levels in the Delaware River were once so low, spawning fish like shad couldn't make it past Cherry Island Flats off Wilmington. Now that wastewater treatment has been upgraded in Wilmington and Philadelphia, oxygen are higher and fish are surviving.
Delaware still has a long way to go.
The total load of pollution to the state's waterways has dropped dramatically, said John Schneider, manager of state watershed assessment. But with so much of the water, an estimated 50 to 80 percent, coming from groundwater, it will take years for the legacy of pollution to filter out of the system, he said.
"We have this huge storehouse of nitrogen in the groundwater," Schneider said.
In Delaware, it's safe to swim in 15 percent of the state's 2,509 miles of streams and rivers. Fish thrive in 6 percent of those streams and rivers. The rest have problems that range from bacteria contamination to legacy chemicals.
The end of the line for one of Delaware's most ubiquitous water pollution problems – high levels of nitrates – may be Delaware Bay and the Atlantic Ocean, where tainted freshwater from underground eventually mixes with seawater.
We've all experienced these seeps without knowing it. Say, you're at Lewes. It's summer and the Delaware Bay is warm. You take a few steps left or right and suddenly, the water sends shivers down your spine.
"That cold spot is groundwater that’s been in the ground for tens to hundreds of years and has seeped up into coastal waters,” said James Heiss, a doctoral student who studies coastal hydrogeology at the University of Delaware.
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“Fresh groundwater that makes its way to the coastline contains chemicals that are of a much higher concentration than those found in the ocean. In Delaware, for example, fresh groundwater may contain nitrate and other nutrient pollutants that infiltrate into the subsurface from sources like agricultural fields or septic systems.”
Once it hits the salt water, a chemical reaction starts that can remove nutrients like nitrates from the groundwater.
The big question is timing. If the mixing zone is small or the groundwater moves too fast, there may not be enough time for the reaction to occur, he said.
Heiss' work is among several efforts to better understand what it will take to repair Delaware's pollution legacy.
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At Auburn Heights, Richard Greene and John Cargill, scientists with the state Department of Natural Resources and Environmental Control, collected fish and water samples last week. Greene uses the samples to see whether legacy pollutants like metals, pesticides and polychlorinated biphenyls are showing up in the water and fish tissues. Greene has been collecting this data for more than a decade and in some places is beginning to see improvements.
"If we do nothing other than what we're doing now, our models predict it will take another 40 to 50 years for PCB concentrations in the sediments to drop to the level that it doesn't result in fish contamination, where we need fish consumption advisories," said Greene, watershed assessment scientist for the Department of Natural Resources and Environmental Control, in an earlier interview.
In some places in Delaware, such as the nontidal Brandywine and Shellpot Creek it's unsafe to eat any fish. Some areas have problems with PCBs and in others, pesticides, mercury or dioxins.
Several places have multiple chemical contaminates that prompted the state consumption advisories. Greene pioneered state and Delaware River Basin Commission research on "fingerprinting" PCBs and tracking down sources, which eventually led to adoption of a new multi-state PCB pollution standard for the Delaware River and Bay in 2013. He also led development of a new cleanup strategy, called the Watershed Approach to Toxics Assessment and Restoration.
There are some success stories with these legacy industrial pollutants. At Silver Lake in Dover, state environmental officials used an activated carbon process developed by researchers at the University of Maryland to address legacy pollution and within a year saw a dramatic water and sediment improvement.
Regular citizens can play a part, too, with programs like the state's Livable Lawns initiative, geared toward reducing excess fertilizer use on residential properties.
And for folks who want to do even more, the state is offering rebates toward the purchase of electric vehicles and installation of home-charging setups.
"We're going to be offering 100 more rebates for plug-in electric vehicles," said Susan Love, with the state office of Energy and Climate.
This is on top of 115 rebates already given out. The program provides $2,200 toward the purchase or lease of plug-in electric vehicles.
Love said one of the biggest arguments against electric vehicle she hears from people is "''I would buy it if I knew there was a place to charge.' We've done a really great job taking the chicken and egg out of the equation."
For years, there were around 60 electric plug-in vehicles registered in Delaware, Love said. But since the rebate program started, the number has climbed to 190.
That may not sound like much in a state where there are over 430,000 registered vehicles, but it cuts the state's greenhouse gas footprint by 830,000 pounds of carbon dioxide a year," said Kathleen Harris, a state climate planner.
Harris said that the state will also help homeowners with rebates to install their own charging stations, which costs between $300 and $700.
It typically costs 10 to 12 cents per kilowatt hour and takes 30 kw hours for a full charge, Harris said.
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"We've beaten the drum really well about changing light bulbs," said Morgan Ellis, a climate policy analyst with the state. The clean car initiative is the next step in getting Delaware residents involved in cutting air pollution.
One reason why state officials are focusing on cars is because Delaware residents drive so much and vehicle exhaust continues to be a large part of the state's air pollution problem.
"We are a very vehicle centric state," Love said. "But we need to shift away from that."
As state officials offer incentives to get cleaner cars on the road, scientists like Heiss work to better understand what happens when upstream pollution intersects with the Delaware Bay and Atlantic Ocean.
Extra nitrogen and phosphorous – found in everything from septic systems and treated sewage waste to animal manure and chemical fertilizers – are a problem because they can lead to algae blooms, fish kills and low oxygen levels in the water. They may even fuel the growth of harmful algae that can be toxic to people, pets and fish.
Heiss took samples at Lewes for a year ranging from high and low tides to gathering data when rainfall was extremely high or low.
“We were trying to get an idea which of those forcing mechanisms – level of tide, size of the tide, or seasonal variability of recharge — are important for controlling the size of the mixing zone,” Heiss explains.
“James’ work shows how dynamic these mixing zones really are," said his research adviser Holly Michael, Unidel Fraser Russell Chair for the Environment and associate professor of geology. "This will allow us to better manage and predict changes in our coastal ecosystems, especially as our beaches and marshes are impacted by sea-level rise. It makes us realize that important things are happening under our feet as we sit on the beach."
Reach Molly Murray at (302) 463-3334 or mmurray@delawareonline.com. Follow her on Twitter @MollyMurraytnj.