Sandusky to clean out sewer lines

SANDUSKY — Once every decade or so seems like an appropriate time to clean out pipes transporting sewage from homes to a plant. And city commissioners agreed, evidenced by them recently signing a contract to clean out what's known as sewer interceptors. In short, an interceptor acts as a major sewer line, receiving wastewater flow from collector lines and then depositing it into a plant. For Sandusky, that's at the wastewater treatment plant on Harrison Street. At the plant, ultimately, all local sewer water gets treated and filtered before being released into Sandusky Bay as clean water again. Collector lines are found along major streets or thoroughfares and links large interceptors to smaller pipes connected to places like homes. Josh Snyder, the city's project engineer overseeing this work, provided an example to help people visualize this underground system. "Think of these lines in terms of a blood circulation system, where the interceptor would be like arteries, collector lines on major streets would be veins and lines on residential streets as capillaries. With arteries partially blocked, there are adverse effects on the capillaries," Snyder said. Officials signed a $690,000 pact with a firm to provide the cleaning. The money comes from Sandusky's sewer account. It's long overdue, Snyder contends, as similar tasks on these interceptors last occurred in 2011. Snyder provided additional insight into the initiative: • The problem: "Over time, in large diameter pipes like these, solids settle out and build up on the bottoms of the pipe. This reduces the effective diameter of said pipes, which ultimately reduces the capacity and how much sewer the pipes can carry." • The fix: "Cleaning these sewers brings their capacities back to the original design intent." • The areas: "Almost all (city) households ultimately have their sewers end up in this interceptor. This work will not interrupt their service, as households are not tied directly into this line, and work will isolate a segment at a time and bypass (the specific) pump around the affected segment." • The timeline: "Spring of this year work should begin, and, depending on the contractor and the weather, we receive, it should conclude this fall." • The upkeep: "This is routine maintenance and, depending on how much debris is removed from the pipes from these last 10 years, we can set a better schedule for this to be cleaned on a regular basis. Yes, it needs to be cleaned regularly. How often is undetermined as there are variables — high bay/lake levels, in particular — that contribute to the rate of debris accumulation. For reference, the 2011 project was the first time it was cleaned in 50 years and required 620 tons of debris to be removed." • The importance: "If this line gets too obstructed with debris, smaller diameter lines along local streets get constricted and their capacities also get limited. If not cleaned regularly, this could lead to flooding and backups in neighborhoods." Getting a generator On a related note, at the same public meeting, officials also approved spending $485,000 in local funds to repair the wastewater treatment plan's backup generator. Aaron Klein, the city's public works director, offered an explanation: • Why it's needed: "When the main power goes out, this generator operates the ultraviolet disinfection system (which can process 36 million gallons per day), two effluent pumps, a 120-volt control panel and a process gate. (A generator) supplies power if the main feed is compromised." • What's at stake, part 1: "If we lose our main power supply to the wastewater treatment plant, we wouldn't have any way to operate the above processes without renting another portable unit. The ultraviolet system operates from approximately May through November, so we need to have a backup system in place to ensure continued disinfection prior to discharging back into the lake." • What's at stake, part 2: "If the standby generator is not in place, the treatment systems will shut down, but the plant would still be operating. We would just be bypassing water that isn't fully treated. The wastewater will not get disinfected prior to being discharged into the bay. First, and less important, is that we would be in violation of our EPA permit. Second, we would be emptying a stream of water that is not fully treated into the bay. It would have gone through all of the treatment processes but the last." • What repairs will occur: "We don't know the exact extent of the repairs needed because it needs to be pulled apart and looked at. It's like having your car break down without knowing why. The mechanic won't come to your house to do the investigation and repair, so you have to have it taken to an appropriate facility. This project includes transporting the unit to a repair facility, evaluation and repair of all damaged parts, and reinstallation at the wastewater treatment plant." • When will work end: "We don't have a completion date yet as that will depend on what parts are needed and their availability. We will be pushing very hard to have it back installed in May but we may need to rent a mobile unit until we get it back."