Drought solution is urged for Delwarare
desalination examined

Staff reporter

Wilmington Mayor James Baker called Wednesday for Delaware and regional water officials to seriously consider helping the city upgrade a water treatment plant to allow it to draw saltwater from the Delaware River and turn it into drinking water.

He said the city has been looking at such a process as part of a study of upgrades to its drinking water system. A $20 million desalination system designed and built by the Canadian company Zenon could be incorporated into a city water treatment plant within a year to provide up to 20 million gallons of drinking water a day during a drought, Baker said.

The ability of the plant to desalinate river water could add to northern Delaware's scant drinking water reserves, helping the city and other municipal and private water systems cope with future droughts, Baker said.

The only reserve water supply for northern New Castle County is Wilmington's 1.7-billion-gallon Hoopes Reservoir.

"Obviously the city cannot do it alone," Baker said. "It is time we face our water crisis head-on and look carefully at the technology."

Baker said he would like to see city, state and New Castle County officials meet to discuss the proposal as soon as possible.

Delaware officials declared a drought emergency in northern New Castle County on Aug. 2, imposing mandatory water use restrictions.

Low rainfall for the last 13 months has left flows in streams and rivers in New Castle County at record low levels. Municipal and private water companies serving areas north of the Chesapeake & Delaware Canal rely primarily on streams for their water.

The water restrictions have succeeded in reducing demand. For the past four days, water use in northern New Castle County has been well below the state's target of 70 million gallons a day. It was 66.5 million gallons Tuesday.

Baker said Wilmington has an adequate supply of water to meet the needs of its residents and businesses for the immediate future. Low flow in the Brandywine, which is the city's main water source, forced Wilmington to begin drawing on the reservoir Aug. 16. United Water Delaware began buying water from Hoopes two weeks earlier.

Wilmington and United Water combined have been drawing about 10 million gallons a day from Hoopes Reservoir and water officials estimate the reservoir has a 70 to 80-day supply at the current rate of use.

But Baker and state and regional water officials said a plan is needed to increase northern Delaware's water supply.

"Anything that will help solve the problem that we are seeing in New Castle County, we would certainly be supportive of," said Chris Roberts of the Delaware River Basin Authority. "We need some long range solutions instead of Band-Aids." The commission oversees water use in all states in the Delaware River watershed, including most of Delaware and parts of Pennsylvania, New Jersey and New York.

Stewart Lovell, water supply manager for the Delaware Department of Natural Resources and Environmental Control, said Baker's desalination idea sounded like a good plan.

The state recently asked an expert with DuPont Co. to do a cost analysis of desalination for the state. That study is not finished, he said.

Costs have risen for other options, such as building new reservoirs or making connections with other water systems in the region. Meanwhile, the cost of desalination has dropped.

"This has been one of the things on our investigation list for a long, long time and I think now the time has come," Lovell said. "It is completely feasible. Probably a very practical solution."

He said high land costs and environmental regulations make building new reservoirs one of the most expensive options. The 300-million-gallon reservoir under construction in Newark will cost $20 million, he said.

Connections with other areas, such as Chester County, Pa., could be useless in a widespread drought like the current one.

"We'll have to do it on our own, rather than looking to our neighbors," Lovell said.

But Lovell said there are drawbacks to desalination, including what to do with the concentrated saltwater or sea salt left over after filtering. The concentrated water could be sent out for ocean dumping but could not be dumped back into the Delaware River. It might be possible to dilute the concentrated saltwater with sewer system effluent, he said.

He also said the estimated costs of operating a plant came out high. Lovell said previous state estimates set the cost of building a plant that could produce 20 million gallons a day at $40 million, almost twice as much as Wilmington's plan. Operating it would cost hundreds of thousands of dollars a day because of the electricity required.

Constance Arter, a spokeswoman for United Water Delaware, which serves much of New Castle County, said the company has investigated desalination, but found it to be too costly.

"It is a very expensive undertaking," Arter said. The company continues to study the option along with other ideas, including a new reservoir near Stanton.

State legislative leaders welcomed Baker's plan but said costs would have to be carefully explored.

Rep. Joseph G. DiPinto, R- Wilmington West, said desalination was worth considering, but past studies have found other options, such as reservoirs, to be more cost-effective. He said a demonstration program might change a few minds. "I do think it is time to go beyond just wringing our hands," DiPinto said.

Reach Sean O'Sullivan at 324-2777 or at sosullivan@delawareonline.com.