Pea soup pond: Questions but not too many anwers
By Lynn R. Parks
Sharlana Edgell used to swim in Beaver Dam Pond. A 1964 graduate of Seaford High School, Edgell said that her friends would gather at a point in the backyard of her parents' home on Greenbrier Lane to swim in the privately-owned pond east of Seaford. "Everybody used to swim here," said Edgell, who moved back into her parents' home three months ago. "I wouldn't swim there now. There's too much algae." "It is like pea green soup," said Margaret Merkley, a resident of Beaver Dam Heights, a community of homes on Beaver Dam Pond at the north end of Williams Pond. "The alga is so dense, and nobody will listen to us about it. What can we do?" Williams Pond is visible from U.S. 13, from the bridge that crosses the Nanticoke River tributary. Its green color is shocking, far from the crystal clear water that many early residents of Beaver Dam Heights remember. "Welcome to Delaware waters," said Roy Miller, state fisheries administrator with the Delaware Division of Fish and Wildlife. He said that most waterways in the state are suffering from an overload of nutrients, which leads to algae growths. "People have moved in, and we are changing the system." "Certainly, there are nutrient problems in most of the tributaries in Delaware," added Craig Shirey, program manager in the fisheries section. Nutrients are primarily nitrogen and phosphorus, ingredients in animal and human waste. When the nutrients, in the form of fertilizer, are applied to lawns or farm fields, the result is lush grass and healthy crops. When the nutrients end up in waterways, the result is plant growth of a different sort, algae. In addition to being ugly and smelly, algae blooms can cause problems in waterways. While the plants give off oxygen in their respiration process during bright, sunny days, when it is cloudy and during the night they suck in oxygen, leading to low oxygen levels in the water and making it difficult for fish to live there. Miller said that as Williams and Beaver Dam ponds are private, no one with the state monitors their fish populations. There have not, however, been any fish kills in the ponds, he said. Fish kills, with large numbers of fish suddenly dead, happen when the oxygen levels drop suddenly. Thick mats of algae also block sunshine from reaching the pond bottom. Grasses which provide habitat and nursery grounds for fish need that sunshine to thrive. Since the dam broke on Hearn's Pond in the summer of 2001 and all of that pond's water rushed into Beaver Dam Pond, the problem has seemed worse, Merkley said. It could be, said Shirey, that nutrients that were contained in the sediment in Hearn's Pond washed into Beaver Dam and Williams ponds with those sediments, making the ponds' nutrients levels higher. Miller said that pond waters can be treated with a copper-based herbicide that kills algae. Cost for the treatment is $100 to $300 an acre, he said. For privately-owned ponds, the pond owners pay that cost themselves. The herbicide needs to be spread as widely throughout the pond as possible, Miller said. That usually means applying it from a boat. If applied as directed, the herbicide is not harmful to other pond plants. While copper can kill fish if applied in excess, if applied correctly it should not harm them, Miller said. But the copper compound just takes care of a symptom of an unhealthy pond. The underlying problem, excess nitrates, is much more difficult to solve. "Really, getting rid of the algae is not taking care of the problem," Shirey said. "The nutrients will still be in the water, and heading for the Nanticoke River. There is really no way to remove them." "We need to radically change the way we do things," said Miller. "That means applying less fertilizer, installing regional sewer systems and pressuring our agriculture community to change nutrient practices. These are all difficult things to do."
Margaret Merkley blames growing development for much of the pond's problems. "Somebody wants to put in a shopping center or housing development, and the state says, 'Sure, OK. Go ahead.' The state approves and approves new development and they all drain into this pond." In recent years, the Wal-Mart shopping center, the Seaford Village Shopping Center and Nanticoke Memorial Hospital's Mears Campus have all been designed to eventually drain into Beaver Dam Pond. Coming soon, Mearfield, with 217 homes, and Gallery Pointe, with 438 homes, will also drain into the pond. All these developments are in the city of Seaford, and are therefore on the city's sewer system. That means that human waste will not make its way into the pond. By contrast, all the homes in Beaver Dam Heights have private septic systems. Old developments like Beaver Dam also do not have storrmwater management plans. The state's stormwater management program was started in the early 1990s. Stormwater retention ponds are designed to capture rainwater that runs off impervious surfaces Ñ roofs, driveways and sidewalks, for example Ñ carrying with it any pollution that is on the hard surface. The water slowly seeps through the ponds, eventually ending up in the watershed. Lyle Jones, program manager with the state Division of Water Resources, who is working on creating pollution control strategies for the Nanticoke watershed, said that, even with the storm water management ponds that are currently mandated by state law, 60 to 70 percent of the nitrogen in runoff from developments makes its way into waterways. Storm water management ponds take care of sediment and much of the phosphorus in runoff, he said. But "most of the nitrogen still ends up in the pond," he said. The pond "is the ultimate repository for everything," Miller added. The state is working on new regulations for the Nanticoke watershed, that would mandate stricter controls of nitrogen from developments. Implementation of those regulations is being held up by a similar process for the Inland Bays watershed, where developers and real estate agents are protesting the state's efforts. Jones expects that Inland Bays process to take about six months; after that, the state will begin work on implementing Nanticoke watershed regulations, developed through the citizen-based Tributary Team. Those regulations could be in place in a year, Jones said. Even so, any development that has its permits before the regulations go into effect will not have to follow them, he added.
Runoff can also carry with it any fertilizer put on crops and lawns that has not been taken up by plants. Farmers are required to file nutrient management plans with the state, indicating where they will apply fertilizer and in what quantities, to ensure that their crops use all the nitrogen and phosphorus that is put on the fields. Bill Rohrer with the state Nutrient Management Commission said that homeowners should also be very careful when applying fertilizer. His department has prepared a pamphlet for homeowners, outlining the dangers of using excess fertilizer. In addition, the University of Delaware Cooperative Extension Service has information available for homeowners regarding correct application of fertilizer, he said. In general, nitrogen should be applied at the rate of 1 pound per 1,000 square feet, Rohrer said. It should be put down only when the plants are green and vigorous, so they can absorb the nutrient readily. "Follow the recommendations on the bag," Rohrer said. "Look at how much is needed, and do some math to make sure that is what you are putting down." Homeowners who use professional lawn care companies should make sure that the companies are certified with the state. A listing of companies that have gone through the education and certification process, required effective January 2004, is on the commission's Web site. Rohrer also recommends that homeowners take soil samples and get them analyzed before they apply anything to their lawns. "It is like tuning up your vehicle for efficiency," he said. "The more you know about the productivity of your soil, the better off we are." Edgell, who is renovating her parents' house on Beaver Dam Pond, said that she is redoing its lawn, which her father kept lush and green. She is considering putting in natural ground covers as well as native grasses that do not require maintenance. She has also recently had a new septic system installed to replace the old, failing one. "Our pond would be much prettier if it didn't have all that green," she said. "In the 1960, the water was crystal clear," added Margaret Merkley. "You could drink it. But the health of the pond went down. "It was so beautiful. But now it sort of seems out of control."
For your information: The Delaware Department of Agriculture has information about best nutrient management practices. Much of it is available on the department's Web site, www.state.de.us/deptagri.
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