County governments are supposed to have plans submitted to the state by the end of June on how to implement the federal Watershed Implementation Plan to improve the Chesapeake Bay’s water quality.

St. Mary’s County government and a public water and sewer utility could be facing hundreds of millions in costs to meet the goals to reduce harmful nitrogen and phosphorus runoff into tidal waters.

The Marlay-Taylor sewer plant in Lexington Park could serve as a new and significant source to reduce the nitrogen load if homes on septic systems near the water are connected.

The cost to connect several large and older neighborhoods near the water could range from $253 million to $166 million, depending on the scope of the work and political will to do it.

By 2030, St. Mary’s County needs to reduce its nitrogen load from septic systems by 85,882 pounds a year.

Seventy percent of the county’s 37,064 households are served by septic systems.

Independently of the Watershed Implementation Plan, the St. Mary’s County Metropolitan Commission is about to start a $34 million project to increase the nutrient removal of sewage. That project will decrease the level of nitrogen and phosphorus, but won’t increase the sewer plant’s capacity.

It is built for 6 million gallons a day and should serve the growing population in central St. Mary’s until about 2018, said Jacquelyn Meiser, director of MetCom.

An expansion adding another 2 million gallons a day to its capacity would allow the Marlay-Taylor plant to meet the population needs up to 2030, said Phil Shire, director of the St. Mary’s County Department of Land Use and Growth Management. “None of this takes into account the [Watershed Implementation Plan] requirement,” he said.

“And that’s the nub of the discussion, is it not?” said John Savich, county government administrator.

“We’re not there even in a ballpark,” Meiser said of a cost estimate for a physical expansion of the plant.

“We do have a dilemma and a fairly long lead time,” Savich said.

Connection fees for new MetCom customers are substantial and are used to pay down the debt on new building projects to expand the system, Meiser said.

The one-time cost for a new residential customer to make a new connection to the MetCom sewer system is proposed to go from $1,700 to $3,700 after July 1.

MetCom needs to know the scope of the expansion needed and timing, Meiser said, to formulate its future budgets. That is up to the county commissioners at the local level.

MetCom does not make the decisions on where water and sewer lines go. It builds the lines where the county commissioners say they should go.

Will septic systems be upgraded to the best available nitrogen-removal technology or be connected into the sewage treatment plant? That is a question for the commissioners.

“I know you all would love to have some decisions made,” said Commission President Jack Russell (D), “but there are so many balls in the air.”

“There has to be paths on different numbers,” said Commissioner Todd Morgan (R). Some will have to upgrade their septic systems because they physically won’t be able to connect to a sewage treatment plant.

“We have to start seeing harder numbers sooner, rather than later. As ugly as they are,” he said.

“We can come up with the ugly numbers,” Meiser said, though they were already presented to the board months ago.

Between the state and federal mandates on the health of the bay, Morgan said, “You’re screwed regardless. There’s nothing you can do, no matter how mad we get.”

“Nobody knows what to do with all these mandates coming down,” Shire said.

Some counties may not submit a plan to the state come June 30, Savich said. What happens to them?

“Could be that the answer is: ‘We can’t do this,’” Meiser said.

“I see the [Watershed Implementation Plan] as a process and not as an event,” said Commissioner Cindy Jones (R).

She called the science behind levels of nitrogen contribution as “very faulty,” and said, “I think the logical science is going to win out the day on this … and some of these price tags will come down.”

jbabcock@somdnews.com