Failure not an option for wastewater utility

Failure not an option for wastewater utility

Faced with shrinking budgets, some US wastewater utilities have defaulted to a “run-to-fail” strategy for assets such as lift station pumps. But the Costa Mesa Sanitary District in California has found a better way to stretch its operating budget. A Xylem TotalCare Preventative Maintenance Agreement saves the district money and ensures equipment uptime.

To prevent sanitary sewer overflows (SSOs) and federal and state environmental penalties, Costa Mesa strives for reliability from the duplex pump stations along its 224-mile (360.5 km) long collection system. This includes scheduling annual preventative maintenance inspections to catch repairs as they emerge.

Costa Mesa sought to further improve its approach after an August 2013 failure at a major pump station led to the largest SSO in the utility’s 70-year history. The uninterrupted power supply unit in a control panel failed, releasing 77,000 gallons (291,000 liters) of wastewater into the storm water system. The discharged wastewater flowed into the Back Bay, forcing the popular Newport Dunes Aquatic Park to close over Labor Day Weekend.

“Our district doesn’t believe in run-to-fail,” said general manager Scott Carroll. “That imposes too much risk and the potential for heavy fines here in California, where regional water quality control boards have policies more stringent than the federal Environmental Protection Agency.”

90-day preventative maintenance inspection

Following the spill, the district’s governing board approved a 90-day preventative maintenance contract to thoroughly inspect 20 pumps in the 11 most critical stations. The inspection contract coincided with Xylem’s introduction of a TotalCare Program for its pump, disinfection, clarification, filtration, and controls installations. The TotalCare program is structured to a customer’s individual requirements, from design and consultancy to energy audits, supervisory service and field maintenance, with Xylem’s nationwide network of offices and field workforces collaborating as a unified team.

Xylem’s Southern California service office submitted a direct bid on the preventative maintenance inspection rather than shopping the repairs out to contractors. Not only did Xylem’s direct bid come in at the lowest cost, but Carroll felt that Xylem, as the manufacturer of the pumps, offered the most expertise and reach in support of the contract.

To meet the contract’s expedited 90-day schedule, Xylem’s Mira Loma, Costa Mesa office supplemented local field crews with highly trained help from the Dallas Xylem office. Each pump station underwent a thorough one- or two-day inspection, pulling each pump to examine controls, electronics, volutes, impellers and other components.

Results of the inspection

“The Xylem field technicians followed a 20-point checklist,” said Darren McMillan, manager of the Mira Loma Xylem office. “Thermal imaging evaluations and hands-on techniques revealed extensive ragging in the check valves and volutes; worn bearings, seals, and O-rings; loose wiring; and an improper lubricant present in the pump sleeves, which would have shortened the life of the pumps.” The Xylem inspection teams also discovered motors nearing failure and a few wetwells that lacked backup pumps.

General Manager Scott Carroll recommended an immediate contract to address all repairs at the stations rather than the few considered the most urgent. The work was let for bid and awarded to Xylem, whose competitive quote again reflected the lower price of a direct contract. Xylem field personnel have been mobilized to complete the tasks by the second quarter of 2014.

“Our board was very supportive of the contract, which I’m confident should prevent another SSO,” Carroll said. “We look at this cost as an investment, not as an expense. That has been and remains our operating philosophy.”

by Simon