05-21-08: Study: Chemical pollutants falling in estuaries

Just as the battle over North Carolina's proposed new coastal stormwater rules heats up, the federal government has released a study citing improvements in the nation's coastal water quality.

Local researchers, however, caution that the improvements documented by the long-term study by the National Oceanic and Atmospheric Administration don't necessarily cover the primary pollutants fouling North Carolina's shellfishing waters, namely fecal coliform and other contaminants washed into waterways after heavy rains.

The continued degradation of the state's shellfishing waters has prompted state regulators, backed by environmentalists, to push for new coastal stormwater rules that are slated to go into effect this summer.

Some coastal officials and members of the development community have called the proposed rules too restrictive. They want to see how new stormwater regulations adopted for New Hanover, Brunswick and Onslow counties last year work before even tougher standards are implemented for new construction within a half-mile of shellfishing waters.

They are pressing the General Assembly to delay implementation of the rules, and legislation to do so was introduced in Raleigh last week.

Federal study shows improvement

The 20-year federal study examined mussels and oysters to measure changes in water quality from 1986 through 2005.It monitored 140 different chemicals in U.S. coastal and estuarine areas, including the Great Lakes.

Gunner Laurenstein, manager of the NOAA Mussel Watch Program, said the study clearly shows that levels of harmful contaminants like DDT and PCBs which were outlawed or severely restricted in the 1970s are dropping across the country.

"The story that you're seeing in North Carolina mirrors what we're seeing nationally," he said. "For these legacy contaminants, you're seeing them going down."

Laurenstein credits the results to environmental laws adopted decades ago and to increased vigilance and enforcement by federal and state regulators.

But Mike Mallin, a water quality expert with the University of North Carolina Wilmington, said the report's findings, while positive, highlight the long road needed to get some of the nastiest pollutants out of the environment.

"The good thing is that the study shows that banned pesticides are going down," he said. "The bad thing is that 30 years after they've been banned, we can still detect them."

Mallin also noted that much of the improvements came from tougher standards for direct dischargers, such as sewer plants or industries that send wastewater right into a waterway.

Newer pollution tied to growth

The harder sources of pollution to control, and the one the coast is struggling with today, are largely tied to increased development.

Dubbed non-point source discharges, they include things such as dog waste, fertilizers and petroleum residue that wash off lawns and roads into local waterways.

Dealing with those pollutants is the crux of the battle over the state's proposed coastal stormwater rules.

Mallin noted that some pollutants tracked by the NOAA study are showing an increase in urbanizing coastal areas, including fast-growing areas along the Carolina coast.

The Morehead City area was one of only two sites nationwide that showed a significant increase in polycyclic aromatic hydrocarbons (PAHs), chemical compounds commonly associated with fuel-burning activities such as automobile exhausts.

Laurenstein admitted that some levels of pollutants are becoming a concern as they enter the environment in increasing quantities, including oil-related compounds and flame-retardant chemicals.

But he said the big picture painted by the study is positive, especially in showing drops in organic contaminants pretty much across the country.

Gareth McGrath: 343-2384

gareth.mcgrath@starnewsonline.com