The grinder pump stations can be easily camouflaged with landscaping.
Under Pressure
Elwood has been operating the new system for several years, and reports a good track record with few hiccups. Most notably, they've experienced some pump failures due to grease.
"This is a situation of user awareness," Hall said. "There are a few multi-unit apartment houses that appear to be dumping grease down the drain. We need to inform the tenants and landlords of the importance of minimizing grease wastes."
It's important to note that in any type of sewer system, grease waste can also clog lift stations and sewer lines, potentially causing major system problems.
On the plus side, Elwood's Public Works Department has largely taken on pump repair themselves. Typically when a pump has a problem, the entire core is replaced in the field, the switch-out requiring only one person, and thereby minimizing downtime. Back at the shop the pumps are easily repaired and put back into service. Any warranty issues are handled by Haynes Equipment.
"We're always here for Elwood," Bellerive said. "But by and large, they've become pretty self-sufficient with running and maintaining the system."
System Comparison
Elwood features such flat topography that its old gravity system required extreme depths to maintain a downgrade. This, in turn, created groundwater inflow problems. With nine lift stations pumping groundwater inflow around the clock, a breakdown of a single station had a catastrophic effect, as the entire system then backed up.
Between the electricity to run the lift stations and the repairs, the old gravity system was literally sending money down the drain.
With the new pressure system, there is a dramatic shift in resource allocation. The grinder pumps run for shorter durations and the closed system doesn't allow groundwater infiltration, so there are no more infrastructure collapses of roadways, mains, or manholes. Overtime is a thing of the past, as grinder pump cores can be replaced during the regular workday.
"We've had some pump failures," Hall said. "But we're able to replace the core quickly and do most of the repairs ourselves. As discussed earlier, a majority of the pump failures are a direct result of grease introduction into the system, which is a homeowner and renter education issue."
Hall anticipates fewer problems as residents come to understand that grease shouldn't be disposed of in the sink.
Elwood's sewer system terminates in a three-cell non-mechanical lagoon, so there haven't been savings on the treatment side, as there are no expenses associated with it. However, Hall notes that the treatment is much faster due to the smaller particulate size, and the ability of the slurry to biodegrade and settle out more quickly.
WW
More WaterWorld Current Issue Articles
More WaterWorld Archives Issue Articles
