Oregon plans to install several temporary flow meters at five locations in the sanitary sewer system to help control storm water inflow and infiltration (I & I) from getting into the city’s wastewater collection system.
The city has established a program of flow monitoring, video detection, and smoke testing to identify I & I sources.
The flow monitoring is required to further define sources of extraneous storm water I & I in the waste water collection system and is a requirement of the wastewater treatment plant Ohio Environmental Protection Agency (EPA) National Pollutant Discharge Elimination System (NDPES) permit schedule of compliance.
The city previously installed flow meters in 2008 and 2009. The additional flow monitoring is needed to further characterize sewer flow where previous data were determined to be incomplete, according to Public Service Director Paul Roman.
“The additional flow monitoring is needed to further define the degree and location of I & I, in particular the South Shore Park area as well as our Navarre Avenue business district,” said Roman at a council meeting on Monday. Last September, the city submitted a Flow Monitoring Plan to the Ohio EPA showing the proposed locations of five meters. Three of the meters will be located in the North Oregon Sewer District in the vicinity of Bayshore and Stadium roads, and two in the Wheeling Street Sewer District along Navarre Avenue in the area of St. Charles Hospital.
Flow monitoring is expected to start at the end of February or early March of this year and continue through the end of June.
“Eventually, we’ll do more to see what are the results of our I & I reduction,” said Roman. “We have seen quite a bit, especially during the dry weather. We think we’ve reduced our flow to the plant by 25 percent. Of course, when it rains, you don’t see that as much. But we know we’re making a lot of progress. There are still some unknowns. And that is what this is really all about. Based on what we find out, we may do more video inspection.”
Smoke testing, particularly in South Shore Park, showed there were several illegal sanitary sewer connections, he added.
The city in the last few years sent out notices to property owners, who illegally connect sump pumps and downspouts to sanitary sewers instead of storm sewers, in an attempt to address inflow and infiltration issues that caused flooding after heavy rain.
“We are getting those corrected. A lot of people have been very good about calling back, letting us know they’ve made the repair and have us go out and inspect the work. It’s been going very well. This is just really a part of that,” he said.
A meter could be moved to another location if there is evidence of more I & I in an area, said Roman.
“If one particular area of South Shore Park has more flow than another, we may move the meters further upstream, then do more video inspections as well,” he said.
City council at the meeting approved a $24,855 contract with Jones & Henry Engineers, LTD., Toledo, to provide professional engineering services to install, operate, and monitor the meters. Funds for the contract were included in the city’s 2013 budget, said Roman.
Jones & Henry will download the data and process it, said Roman. “We’ll write the report ourselves to the Ohio EPA. We’ll be required to do that. It’s pretty cost-effective. They will certify the results.”
Administrator Mike Beazley said there has been a lot of improvement in the dry weather flow to the plant since the work upstream.
“It really shows the work pays off. It was really the confidence the state had in Oregon’s work upstream that has kept Oregon from having to invest a lot more in this next round of NDPES permit,” said Beazley. “That’s made a big difference. So this work upstream really pays for itself in two ways: It helps protect our neighborhoods from flooding, but it also keeps taxpayers and rate payers from having a very large burden at the plant as well. So it pays for itself twice.”