At a Morgan City Council meeting Tuesday night, it was decided that new development will have a tough time garnering approval as the city’s sewer lagoons approach 80 percent capacity.
“We are not at crisis level, but we do need to have a plan in place to take care of this,” said Mayor Ray Little.
Figures presented by city employee Jaime Grandpre showed that there is a dire need of additional aerators. Grandpre recommended that the city not allow any large developments to connect to the system until the process has returned to normal.
Typically, the Utah Division of Water Quality encourages cities to begin designing for expansion when treatment facilities have reached the 80 percent capacity mark.
An emergency dredging process with a fairly large price tag is already in the works, so the council was reluctant to “throw more band-aids” on a system that will soon be replaced. However, Grandpre reminded them that even if the city were to start the process in January, with all the steps that must be taken, “we are still five years away from completion of the new mechanized system.”
“The ponds have gone septic and are no longer functioning as required. As a result, the effluent does not meet existing permit limits for dissolved oxygen concentration, E-Coli and other parameters,” according to the document presented by Grandpre. After the sludge is pumped out of the septic ponds and placed in the recently rehabilitated pond, performance will improve. However, the cold weather will limit natural photosynthesis, which will result in an increased reliance on mechanical aeration.
There are 12 aerators in the lagoons, some are still “splash” aerators, which is an outdated technology that can no longer be repaired. Grandpre informed the council that these aerators do not support oxygen transfer, so even if they could be repaired, they need to be replaced to meet regulations.
It is projected that there are 4,129 people currently living in Morgan City with an estimated 1,432 equivalent residential units (ERUs) utilizing the sewer system. This number takes into account all the currently approved lots including the proposed apartment complexes. The current treatment facility has a design capacity of 2,000 ERUs, but the state considers the design capacity of the lagoons to be 1,800 ERUs, which puts Morgan City right on the cusp of that magic 80 percent.
The Island Road lift station also needs upgrading. The facility is 30 years old and is showing signs of severe corrosion. The piping and access hatch, as well as the grinder and generator, need to be replaced and other components should be updated, according to documents prepared by Engineer Gary Vance.
“In my opinion, this is the highest priority,” said Grandpre. “This lift station is a stand-alone issue. It needs to be replaced regardless of what happens with the sewer facility itself.”
Other vital improvements that are lower on the list include a larger chlorine contact pipe, a larger basin for the back end re-aeration system and repairing the existing clay liner in the pond that is used to store water that is out of compliance. This liner appears to have been damaged when the Northwest lift station was constructed in 2011 and is leaking.
According to submitted documents, Grandpre and the engineering group he is working with believe that limiting additional connections and adding new aeration options to improve lagoon recovery time will put Morgan City back where they need to be until an updated sewer facility can be completed.