Town staff working to correct high levels of phosphorus at wastewater plant

Town crews have been actively working to adjust phosphorus levels that have spiked in recent months. As was noted in the town’s utility report, the average level for December was 0.62 milligrams/per liter. While still high, it was a downturn from November’s total of 1.42 mg/l.The state regulations for treated waste water effluent discharge into the bay specify a maximum annual average of 0.3 milligrams/liter. According to assistant town manager Bob Panek, interim testing in January indicates that the concentration is now less than 0.3.

Panek also told the Mirror that the spike in phosphorous concentration appears to correlate with the failure of several mixers in the bioreactor tanks. The mixer failures, coming so close together exceeded the number of spares the town had on hand for replacement. “A new model has been installed to replace them, and the original mixers have been repaired and are now available as additional spares…the phosphorous levels have improved markedly,” Panek said.

The staff is investigating other potential causes of the spike. Another cause may be that the feed system for the chemical that is used to precipitate phosphorous out of the water prior to discharge may not be working properly.

During Thursday’s council meeting, Mayor Proto was adamant about first fixing the issue, but also determining what is the actual root cause for the failures. Councilwoman Natali also suggested that the monthly utilities report should include a running average of readings from the plant.

The concern of both is warranted, as was stated in minutes of the December council meeting, “Councilman Bennett asked about the high phosphorus average of 1.42. Dave Fauber stated that in August, the phosphorus numbers went up considerably, most likely because six mixers had to be pulled from the tanks for repairs. Once the numbers were elevated, it was difficult to get the average back down within acceptable limits. Staff was working with the engineers to rectify the problems. There was some discussion of possible fines which amounted to approximately $10k per tenth of a milliliter above the accepted annual average of .3 mg/l.”
If fined, given the length of time the plant has been out of compliance, the amount could be close to $30,000.00.