WASTEWATER TREATMENT SYSTEM IS AGING
Old sewer parts need replacing
Certain parts of the village wastewater system are a decade old now and need to be replaced. Such a proposition came before the village council July 1 and it passed. The solution is expensive, in part, because the village is upgrading to long lasting, stainless steel parts (at right) instead of plastic (on left). But, stainless steel doesn't come cheap.
The Village’s Wastewater Department had identified malfunctioning polyethylene check valves within the village’s wastewater low pressure force main. Check valves generally are installed in pipelines to prevent backflow. A check valve is basically a one-way valve, in which the flow can run freely one way, but if the flow turns the valve will close to protect the piping, other valves, pumps, etc. Rubber seals on the flappers are deteriorating and losing its seal while allowing effluent to back flow into the grinder pump pits.
These failures have been more frequent lately, according to village public works director A.J. Engelmeyer, and have the potential to cause costly damage if they result in sewer backups into residences or businesses and sewer spills into neighboring areas or waterways. It is estimated there may be as many as 600+ valves installed as a component of the original system.
To be proactive, staff has proposed a sampling of check valves to determine the cause of the failures and see if those experienced to date are isolated issues or if we can expect the check valves to begin failing more regularly as they reach a certain age. If problem poly check valves are identified, then they would be replaced with a stainless-steel valve.
The village has been installing stainless-steel check valves at new connection points over the past few years. The village entered into a Continuing Services Agreement with Page Excavating, Inc., an Islamorada firm, effective May 24, 2018. Pursuant to the CSA, Page has completed the previous replacements of the malfunctioning poly check valves on a project-by-project basis, and the work has been overseen by village staff.
Work Authorization No. 1 under the CSA to replace vacuum pits in the North Plantation Key portion of the wastewater system has been completed. The attached resolution provides approval for Work Authorization No. 2 to provide parts and labor to replace 100 malfunctioning poly check valves throughout the Villages Wastewater Low Pressure Force Main in the amount of $135,000 or $1,350 per check valve.
The proposed cost of Work Authorization No. 2 with Page is for a not-to-exceed fee of $135,000. The purchase would be recorded in the Wastewater Enterprise Fund’s Capital Outlay – Infrastructure account. At the end of the year, the expense would be capitalized as an asset of the village-wide wastewater collection and transmission system.
Wastewater rates would be the funding source for the project. Village staff would evaluate and consider Stewardship Act grant funds through the Florida Department of Environmental Protection and/or Florida Keys Water Quality Improvement Program grant funds from the U S Army Corps of Engineers to fund the project as those funds become available.
Village Wastewater staff is to oversee the completion of the work and determine the cause for failures.
Lower Matecumbe Key
Residents of Lower Matecumbe Key (LMK) voiced their concern July 1 about ongoing aging issues with grinder pumps installed on that island’s sewer system. They, too, must be addressed, they said.
Engelmeyer said the best system for addressing grinder pumps is having property owners call in when the grinder pump warning sounds in the neighborhood.
A LMK resident said, “In my neighborhood, there are times when I am the only one in range. A neighbor's warning sounded when I was the only one around. It took me an hour to figure out where the blaring sound came from. I walked from house to house trying to figure out from where the sound came and had to almost put my ear to the mechanism to assure it was the right house, not the house 20 feet away. That's when I learned the telemetry system was broken as that blaring sound went on for a long time until I took the initiative to figure it out… only because my dog was going nuts. Initially, I had no idea it was a grinder pump malfunctioning.”
Her point is this warning system for malfunctioning grinder pumps is dependent on concerned neighbors who are around to hear and address the siren sounds in their neighborhood, and/or on dogs who hear it and are annoyed by the sound. A telemetry system, on the other hand, is tied into wastewater monitors. Are dutiful neighbors really a great way for a municipality to deal with wastewater malfunctions?