By Grace Moore
Members of the Moorcroft governing body met with HDR Engineering’s Heath Turbiville and Nick VanWyhe last Tuesday for an update on the mandatory upgrading of the town’s lagoon. These upgrades will not address the problematic ammonia issue the town currently faces, but will r
eplace the failing aeration system, dredge the cells and prepare the site for future implementation of DEQ-required systems.
HDR advised that cell two be closed first to be dredged and the new aeration system installed, allowing cell one to maintain the existing flow until cell two can carry the load. This will ensure uninterrupted aeration and bring both cells one and two to comparable systems. A bypass system is already in place to facilitate such a manipulation.
The existing chlorination facility on has not been used for several years and is not adequate for the coming requirements, so the plan calls for removal of the old building to make room for a sturdy shelter for the significantly larger aeration blowers. Two of the three planned blowers will fulfill the current aeration demand with the third as a back up and for any secondary system that will be required.
“Since you’ll need three of them eventually, we want to put in all the pads, all the piping and make sure it’s hooked up and ready to go,” VanWyhe stated.
The engineers shared two possible alternatives for a new chlorination system; they are both “contact chambers”, thus allowing the waste water to make contact with the chlorine on one end and the sulfur dioxide (negating the chlorine) as the water exits the chamber.
The first option is constructed of concrete and starts at one corner with the chlorine and forces the water through an N shape within the construct before releasing through the sulfur dioxide at the other end; this chamber is significantly more difficult to maintain and more expensive to build than the second option.
The second option consists of a pipe and two smaller concrete “boxes”; the pipe is laid in a common trench and does not require walls; the maintenance is less expensive because no algae can grow where the water is not exposed to sunlight so less chlorine must be used.
Three pipes would be laid: the chemical feed (chlorine), the de-chlorination and one for the PH control (which is not needed right now). Any leaks throughout the entire “pipeline and boxes” can be quickly ascertained and corrected with minimal effort.
In further preparation for possible future requirements, the engineers’ plan allows for the installation of a cistern for potable water for drinking and any lab work that may be needed. However, VanWyhe explained that this type of addition can easily be removed for to better facilitate funding.
After further discussion regarding this first step of the first phase of the lagoon upgrade, a concern was voiced about the notable absence of the town’s new discharge permit from the DEQ. As of this report, the DEQ has yet to respond.