Cedar Creek officials: plant running smoothly

Officials from United Water provided residents with a status report on the workings of the Cedar Creek Water Treatment Plant at a public meeting on June 2. Dan Ryan, plant manager, told residents the sewage treatment plant has had no violations to its SPDES, or state pollutant discharge elimination system, permit this year.

The plant continues to remove 95 percent of Biochemical Oxygen Demand and 96 percent of suspended solids, Ryan said. Pace Analytical Labs does the required testing of samples as required by its SPDES permit, and the Nassau County Department of Health continues to monitor for coli form.

Ryan reported that the maintenance department, which historically was undermanned, is now fully staffed and “all our stock has been inventoried and placed into our computer system,” Ryan said. The computerized maintenance management system “allows us to automatically reorder parts,” he said, and allows for a faster turnaround when something breaks. In the past, there had been considerable delays to repairing equipment because parts were not in stock.

Several projects are under way including the replacement of all four bar screens, and there is ongoing restoration to the building where the bar screens are housed.

“Are these bar screens the same ones that they use at Bay Park,” asked Phil Franco, co-chairman of the Cedar Creek Oversight Committee, referring to the county’s other sewage treatment plant. Bar screens remove large pieces of debris when the sewage first enters the plant.

Joe Davenport, United Water employee, explained that there are two different types of bar screens and the ones at Cedar Creek are designed to compliment the upgrades now being made in the building where the bar screens are housed. “These screens discharge at grade,” he said.

Presently, United Water is working on an odor control project at the aeration tanks and this summer will continue to clean out the digesters.

“This can be stinky,” United Water spokesperson Michael Martino warned residents, “but we will do our best not to do any work during the July Fourth weekend.”

The digester spheres are also undergoing rehabilitation. Two of the nine spheres are completed. However, inclement weather this winter slowed down the repairs. Then in the spring “seagulls came in and built their nests. There are eggs in there,” said Ryan. “We had to call in the USDA to address it and hopefully we can finish these spheres soon.”
United Water will hold another informational meeting for the public in September. At that time the public will be invited to take a tour of the plant.

How sewage is treated at Cedar Creek

Preliminary treatment consists of a screening chamber, mechanically-cleaned bar screens, and aerated grit removal. Screenings and grit collected are compacted, dewatered, and disposed of off-site. Influent flow is pre-chlorinated after screening.
Primary treatment is accomplished through primary sedimentation tanks, which remove about 30 percent of the Biochemical Oxygen Demand (BODS) and 45 to 55 percent of the Total Suspended Solids (TSS) from the influent wastewater. Sludge collected from primary treatment is pumped directly to the primary digester. After primary treatment, wastewater flows to the aeration tanks and then the final sedimentation tanks. Either conventional activated sludge or a step-feed mode can be used during secondary treatment. Effluent passes through traveling water screens to remove any remaining solids before moving on to chlorination facilities. Screenings and sludge collected are processed in the sludge thickening units before being transferred to the primary digesters.

Plant effluent is disinfected with sodium hypochlorite prior to being discharged through an outfall extending 3 miles into the Atlantic Ocean.

Sludge generated at the plant is pumped to the five primary digesters. Digested sludge is allowed to separate and settle in two secondary digesters, and is subsequently stored in two sludge storage tanks. All digesters are equipped with floating covers. The plant’s Power Generation Facility uses methane gas produced by the digesters. Digested sludge is dewatered using belt filter presses and trucked to an out-of-state facility to be land filled or for further processing into soil amendments.