FARMINGTON – Selectmen on Tuesday reviewed a plan to improve the flow of treated water leaving the wastewater treatment plant.

Officials are contending with heavy silt that travels down the Sandy River and covers diffusers – pipes extending from the plant into the river. By blocking the diffusers, the silt prevents the treated water from properly leaving the plant.

Officials, in collaboration with the state Department of Environmental Protection, have a plan to remove the sand and silt, extend the diffusers, and set them at either a 45- or 90-degree angle. Engineer Michael Stein with the Portland engineering firm of Woodard & Curran explained the proposal to selectmen Tuesday.

A quote from the Ted Berry Co. of Livermore for a total of $26,000 to complete the work was included in the plan. Costs include a dive team, a construction crew, materials to extend the diffusers, and riprap to protect the diffusers, Stein told the board.

A sum of $18,241 was left over from a previous treatment plant project and could be used, Town Manager Richard Davis said. Possible funding from DEP will be explored for the remaining portion needed.

Whether the sand dredged from the river will be available for the town to use will be addressed, Stein said. DEP wants to look at it first to see if it’s hazardous. If they find it unacceptable, the town will also be responsible for the cost of removal, he said.

The discharge system was installed two years ago when the state required the town to change the previous discharge location, Superintendent Steven Moore has said.

Earlier this year, the discharge pipe was not working properly, backing up into the plant. After the pipe was flushed in January, the problem appeared to be solved. Then in March, the same problem occurred again, he said. Divers found several feet of sand covering the outflow pipe, he said.

While there is no guarantee that the new plan will solve the problem, Selectman Dennis Pike asked Stein how certain he is that this is the answer.

Stein referred to an update in the plan that suggested three additional items be added, including a field test on the depth of sand that has only been estimated; a geologist review of part of the Sandy River by University of Maine geologist Tom Eastler; and a better estimate of the size and slope for the riprap suggested to protect the diffusers.

“A total of $340,000 was spent on the (previous) project that didn’t work and now another $26,000 is needed with no guarantees it will work, how long does the town have to continue to be responsible?” Selectman Nancy Porter asked.

Seeing no alternative, the board agreed to continue on the course of action recommended since the sand has not naturally flushed itself from the site as the board had previously hoped.

In other business, Public Works Director Denis Castonguay and Davis discussed options to avoid an overdraft in the department’s motor fuel budget.

While the department benefits from purchasing fuel from SAD 9, a large amount of fuel was needed in February, Davis explained as he quoted the amount needed in January was 2,783 gallons at $3.09 per gallon compared to 7,128 gallons at $3.15 in February and 1,231 at $3.64 in March. The town also received billing this month for fuel received in December, he said.

Castonguay estimated a need of $22,000 for fuel until the end of the year.

To cover that amount, Davis and Castonguay recommend using money from the Urban Renewal Initiative Program for paving of Church Street and part of the work planned for the Whittier Road to free up some funds, postponing sidewalk repairs in town, and pursuing other issues such as energy conservation.