The 28th annual Christina River Watershed Cleanup sent volunteers to pick up trash at 13 sites in northern New Castle County Saturday. Experts say the river's main problems are excess nitrogen and sediment, largely from farms upstream.
According to state officials, more than 350 tons of trash have been cleared from the Christina River and several tributaries since the annual cleanup started in 1992.
John Jackson, senior research scientist at the Stroud Water Research Center, says trash clean-ups are important for raising awareness about stream health.
“I think they’re one of the most visible ways we can draw attention to the stream, to the health of the stream, and how the community has a role in protecting that stream and cleaning up that stream,” said Jackson. “If we start that conversation, then when we get to these pollutants that we can’t see, they’ve already been engaged. They know the big stuff is out there, of course there’s going to be little stuff they can’t see.”
He adds trash cleanups along inland rivers can also help keep trash out of the ocean. “The streams and rivers are major sources of plastics and other trash in the oceans,” he said. “So our local trash problem has the potential to become an ocean trash problem.”
Jackson says nonpoint-source pollution — like runoff from agriculture or lawn care — is a bigger challenge for water quality locally.
“Most of these streams struggle a death of a thousand cuts,” he said. “In one day it might be a landowner who had a lawn care company come in and do their herbiciding and insecticiding on a rainy day and most of that washed in … Or you had a manure application in the winter that unfortunately had a nor'easter blow in and wash a lot of manure into the stream.”
Gerald Kauffman, director of the University of Delaware’s Water Resources Center, says water quality in the Christina River and White Clay Creek has improved over the past few decades, but still has a ways to go.
Kauffman says he would give the health of the Christina River a grade of C-plus to B-minus. “It’s got a ways to go to get to the grade that we’d like to get to, which is an A, which would be fishable, swimmable and potable— or drinkable. ”
Kauffman rates the health of White Clay Creek, which provides drinking water to most of the City of Newark, as a “solid B.” He adds that the health of both waterways is “above average.”
“We do have some high levels of nitrogen coming down from the agriculture in Chester County,” said Kauffman. “And we also have some high sediment coming down as well. It's coming from some of the farm fields, and it's also coming from the stream banks itself as it erodes in the urban areas.”
Excess nitrogen can cause algal blooms, like the one at the Newark Reservoir that impacted a triathlon in 2017. Kauffman says excess sediment is a problem for fish that lay their eggs in the sand at the bottom of rivers.
Kauffman says municipalities in New Castle County are beginning to work with these upstream sources to prevent pollution. He says solutions that reduce agricultural runoff include winter cover crops, better barn designs, and manure holding ponds.
“It takes much less money to prevent the problem from ever occurring up in the headwaters there than build these multi-million-dollar water treatment plants downstream to take all the pollutants out,” said Kauffman.
The Christina River Watershed Cleanup will conclude at White Clay Creek state park this Saturday.