Brandon Mahon, left, project representative for Anderson Perry, and project contractors Steve Lindley and Lee Ricker discuss a detail of the ongoing Cove wastewater expansion project Thursday. (Chris Baxter/The Observer)
Although the City of Cove will receive two change order requests totaling an estimated $90,000, the $1.6 million wastewater expansion project is progressing on time and may come in under budget due to an initially low bid from the contractor.
“It is proceeding very well and the city is very pleased,” said Mayor Lyndon Rose.
The project involves creating two new storage ponds for treated wastewater. The ponds will cover approximately 18 acres and be 6- to 7-feet deep at maximum capacity. Treated wastewater from the existing treatment plant will be piped to the new storage facility and used to irrigate crops not intended for human
According to Brad Baird of Anderson Perry and Associates, earthwork for the new storage ponds is 40- to 50-percent complete. The base of the ponds has been formed and work will begin to shape the dikes that make the walls. The pipeline connecting the current lagoon to the new storage ponds is complete. Archeological monitoring is nearly concluded with nothing of significance found at the site.
“Things are going really well,” Baird said. “The hardest part is in the rear-view mirror.”
Baird presented a request to Cove City Council Tuesday evening for a change order totaling more than $35,000.
“This change order came about because I wanted to simplify the disinfection system and make it user friendly,” Public Works Director Mike Brown said.
The change order includes an upgrade to a new pump that will allow the disinfection process to move away from chlorine tablets to a liquid chlorination system.
Brown told the council that chlorine tablets make monitoring difficult resulting in over- or under-disinfection.
“It is a good improvement for this system,” Baird said. “It is user-friendly and almost automated.”
Mud — the consistency of an uncooked brownie — will force a second change order request.
Excavators uncovered a particularly gooey mud in one corner of the future storage ponds that caused their equipment to sink as high as the door.
It appears that water was trapped above a clay layer and then mixed with organic matter that was sealed from above by volcanic ash creating an anaerobic environment. Without oxygen the organic matter would not decay. What resulted was some pretty powerful mud.
“It would pour out like a thick milkshake,” Baird said. “This is a perfect example of unforeseen conditions.”
Baird said that while the mud will cost the city more money, it will not delay the project. Baird estimates the mud may cost an additional $50,000 due to the extra time and equipment needed to excavate the wet corner.
The low permeability of the clay — which prevents water movement — and the self-sealing properties of clay when wet, make for a great liner. The clay will be used to line the bed and walls of the wastewater storage ponds.
Baird told the council that even with the two change orders, both the schedule and the budget are right on track.
“It is about 40 percent done, if you track it relative to expenses; based on contract time it is about 40 percent done, too,” Baird said.
The contractor, Steve Lindley Contracting, Inc. of Union, bid the project for less than what was originally budgeted. This created a cushion of about $114,000 in the budget, which may absorb the two change order requests without dipping into extra contingency funding. In addition, a couple items, including archeological monitoring, may come in under budget.
“If we get this project done for $1.5 million, that is what our loan will be, so there is an impetus to save money,” Baird said.
The final loan amount will dictate the rise in residential and commercial sewer rates.
“The lower the cost, the cheaper the rates will be,” Rose said. “The loan company tells us what we have to charge.”
Construction of the new storage ponds has had a target completion date of mid-November.