What should you do when your town is under multiple and ongoing consent orders for violations of its Montana Pollutant Discharge Elimination System (MPDES) wastewater discharge permit?
Excessive lagoon sludge accumulation contributes to the poor performance of any treatment system, particularly in winter. Removing sludge from the lagoon cells will improve treatment at the facility and help to address some of the violations in the Department of Environmental Quality (DEQ) enforcement action.
The City of Harlem, Montana has a wastewater treatment system consisting of a three cell partially mixed aerated lagoon system constructed in 1985. The lagoon system discharges to the Milk River under wastewater discharge permit MT0021270. The sludge removal project is the initial step in a comprehensive facility upgrade for the City of Harlem.
Stahly Engineering & Associates, Bozeman, MT and City of Harlem staff conducted a lagoon survey in December 2009. Each cell was sampled in multiple locations using a sludge judge probe assembly operated from a small boat. Solids volumes were calculated using the lagoon bottom area multiplied by the sludge depth. A volume allowance was added for solids accumulated along the sloped sides. The aerated ponds contain significant quantities of settled solids 1 to 2 percent in concentration and occupy between 27 and 58 percent of available volume.
Jim Bridges, a Geotube distributor doing business as Clearwater Dewatering, in Nampa, Idaho, brought together a number of parties to collaborate on the City of Harlem’s Sludge Removal Project and turn it into a training opportunity.
WaterSolve, LLC, a national leader in dewatering operations located in Caledonia, Michigan, and a master distributor of TenCate GeoTube products bid the project. The project is financed by a grant from the Renewable Resource Grant and Loan (RRGL) program of Montana’s Department of Natural Resources.
A subcontractor to WaterSolve, SRS Crisafulli, Inc., Glendive, MT, a manufacturer of sludge removal dredge systems, will be providing the dredge, float line, and operator/trainers to this two week project, located 270 miles northwest of the Glendive factory, just the other side of the Charles M. Russell National Wildlife Refuge.
Montana Rural Water System’s Dan Kramer has qualified a training program, Sludge Removal for Small System Wastewater Operators Workshop, as a Continuing Education Credit (.35 CEC's)for Montana Certified Operators, approved by the Montana DEQ. He is offering training at the jobsite with presentations at City Hall. The training will be offered on Thursday, June 6th, 2013. Training is geared towards small and medium sized wastewater systems. The training will provide information about the importance of the Notice of Intent, daily monitoring of equipment calibration and operation, a discussion of sludge removal, and the on-site demonstration of the working sludge removal system.