Along with all the rough grading and excavation, the liner installation in two new aeration pond cells is near complete at the wastewater treatment facility upgrade in New York Mills.
After the major milestone of moving over 300,000 cubic yards of soil was reached, the primary focus shifted to the installation of the pond lining system. This system consists of geotextile fabric, which is placed on the native subgrade, and a heavy PVC liner. The geotextile fabric essentially reinforces and protects the PVC liner from puncturing.
As the liner is installed, the contractor is beginning the placement of the granular liner cover which consists of 12 inches of screened sand. Upon completion of the liner cover, which is expected to take 3 to 4 weeks, rip rap will be placed on the interior slopes of the ponds. This will protect the pond slopes from erosion.
The last major item then to be completed will be the installation of the aeration process piping within the ponds. This piping delivers arge volumes of air from blowers housed in a separate building to the sewage stored in the new ponds. This aeration process aids in the treatment of the sewage and helps to control the odors. Once all of this equipment is installed, both ponds will undergo a water-balance test. This basically involves filling each pond with over 25 million gallons of water and monitoring the level for several weeks to ensure that they do not leak into the subgrade soils.
Other more minor work is continuing on the bower/headworks building which will house the four aeration blowers, screening equipment, and the supervisory controls system for the entire treatment facility.
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"As a whole the project is progressing very nicely," says Jon Pratt, of Ulteig Engineers. "It is slightly behind schedule but the contractor is working as quickly as possible towards the final completion which should be sometime in late September of this year. The project remains on budget and the end is now in sight. I continue to be very impressed by the contractor. They are a first class operation and are truly committed to delivering a good facility to the City of New York Mills."
