Volunteers for the town have started testing estuarine waters to learn more about sources of potential pollution and possibly boost water quality in the Davis Creek watershed.
“We want more people to become advocates of the watershed they live in,” said John Michaux, stormwater coordinator for the Town of Oak Island.
In November, the Stormwater Advisory Board began testing six points twice a month. Michaux said tests have been taken during a falling tide and plans call for timing some tests just after a rain.
Volunteers are checking for fecal coliform bacteria, salinity and the presence of optical brighteners—chemicals used in detergents to make clothing and colors appear brighter.
There are no firm conclusions yet, but early tests seem to show that water quality starts out good toward the western end of the island, which experiences the best flushing and influx of sea water. As sampling moved east, both coliform and brightener numbers seemed to increase, in some cases far exceeding the single-sample limit for swimming of 400 colonies per 100 milliliters of water. Some of the higher numbers of contaminants were in the area of SE 40th Street, the eastern edge of the navigable part of Davis Creek.
Fecal coliform are used as an indicator because they come only from the waste of warm-blooded animals. Pets, birds and wildlife can be causes of fecal coliform, as can sewage leaks or failing septic tanks.
Brighteners, however, have no natural source and are generally associated with septic wastes or direct discharge of detergents into surface waters.
Michaux said there are some houses in the area that have not yet connected to the town’s sewer system, but the exact number is unknown.
“We’re trying to have a better perspective on what the cleanliness issues are with the water,” said Bob Yingling, chairman of the Stormwater Advisory Committee. “We’re just beginning the process and trying to get some baseline data.”
Yingling said the town might not be able to solve the pollution issues but it is critical to have the data first.
Michaux said that state regulators test the water near Middleton Bridge monthly, but the committee was hoping to obtain a broader picture. In the future, the town might be able to use street-ends to slow and filter stormwater that is now going straight into the creek. Taking advantage of such possibilities for reducing pollution was among the recent suggestions made to the town by the Ocean and Estuarine Access Committee.
“We want to look at the trends and we want a long-term program,” Michaux said. “There might be some opportunities to mitigate the negative impacts. … I am excited about it, but it will be a challenge to find ways to improve.”
Michaux credited the committee with working out a testing protocol. Other members are Roger Bokeny, Joey Brochure, Lee Butzin and Malcolm Morrison. Jim Atack has also been assisting, Michaux said.