Land application of wastewater utilizes nutrients
by Tom Chillemi
|Wastewater from Kilmer’s Point and Cedar Pointe subdivisions, located about three miles west of Urbanna, is aerated in the two smaller lagoons and stored in the larger pond until it is sprayed on a 14-acre grass field. The grass takes up the nutrients in the treated effluent. (Photo by Mike Kucera)|
For more than 18 years, Kilmer’s Point and Cedar Pointe subdivisions near Urbanna have used air, sunlight and land to treat their wastewater. It is sprayed on a 14-acre field where remaining nutrients become fertilizer for plants.
The nutrients in treated wastewater “are only resources that are out of place,” said Dan Gill, a former county supervisor who has advocated land use application for more than 25 years.
In 2011, the state will require that the nutrients phosphorus and nitrogen be nearly eliminated in treated wastewater, a difficult and expensive job, said Middlesex County wastewater consultant Roger Hart.
Gill, a farmer, said he believes strongly, from many years of experience, that land application is the most appropriate way to dispose of organic waste. The land application facility that serves Kilmer’s Point and Cedar Pointe subdivisions is built on Gill’s property at Remlik, about three miles west of Urbanna.
“Land application is a proven and viable alternative to the traditional disposal of effluent through a pipe into nutrient enriched waters, such as Urbanna Creek,” Gill said.
Middlesex County has an application pending before the State Water Control Board on a proposed 39,900-gallon-per-day wastewater treatment plant for Saluda. As now proposed, the treated effluent would flow into Urbanna Creek.
Opponents argue that Urbanna Creek does not flush effectively and nutrients in the effluent will be trapped in the creek water and the bottom sediment—to the detriment of marine life. Related article: Citizens oppose more effluent in Urbanna Creek
“I feel a whole lot better putting it on the ground and letting it soak in, than putting it into a creek,” said Charlie Powell, president of the Kilmer’s Point Homeowners Association.
Powell said there are 86 homes currently hooked to the treatment system, which has a state permit to handle 32,500 gallons per day, or up to 109 homes.
The wastewater is first ground into a finer liquid, and then pumped about two miles to the first of three lagoons, which cover a total of 12 acres, said Powell.
The first and second lagoons each have four pumps that continually inject air into the wastewater breaking down the organic material and encouraging the growth of good bacteria, said Gill. The difference is the wastewater stays in the lagoons for months. Some is lost to evaporation, and the few heavier particles in the evaporated effluent fall to the bottom.
The third lagoon is a 2-million gallon holding pond that “polishes” treated wastewater. By the time the water gets to the holding pond, it’s just water with some nutrients, he said.
The wastewater is not sprayed in the winter when plants are not growing, or when the ground is wet, Gill noted. The idea is to spray the water when plants are growing, and the plants will drink the water and nutrients so they don’t leach into ground water.
The state requires that the wastewater is disinfected, which is done with chlorine before being sprayed.
The system is designed to be more forgiving than package plants in terms of high and low wastewater flows, Gill said. Package plants need a minimum flow for treatment processes to take place.
According to the DEQ, the permit for the Kilmer’s Point and Cedar Pointe treatment facility has the following requirements (among others):
- The application rates cannot exceed 0.25 inch per hour, 1 inch per day, or two inches per week.
- The wastewater itself is tested daily and monthly for 7 parameters.
- Since groundwater contamination is a potential problem with spray irrigation systems, there are four groundwater monitoring wells on site that must be tested on a once-per-three-month basis. There are seven different parameters that are tested.
- The soils within the spray field are tested on a once-per-six-month basis for 18 different parameters.
Related article: Citizens oppose more effluent in Urbanna Creek