The township will host a Public Information Centre on Phase 1 and 2 of a Municipal Class Environmental Assessment (Class EA) being conducted to evaluate alternatives to expand the capacity of the Mapleton Wastewater Treatment Plant.
The event will be held on June 16 at the Mapleton Administration Centre on Sideroad 16.
The study is not recommending the township proceed with an innovative program of using treated wastewater for irrigation in an effort to increase capacity, instead focusing on expansion of the current window of opportunity to discharge effluent into the Conestogo River.
Mapleton’s lagoon-based wastewater treatment system has been operating at or near its rated capacity of 750 cubic metres per day for a number of years, effectively halting growth in the urban areas of the municipality.
The study looks at ways to increase the treatment capacity to 1,230m3 per day in order to accommodate the township’s projected growth until 2031. In addition, the Drayton Pumping Station does not have sufficient capacity to service the village’s projected population.
Arun Jain and Jean Louis Gaudet of Exp Services provided council with an update on the project at the May 26 council meeting.
The study examined three alternatives for upgrading the water pollution control plant: pre-lagoon nitrification, post-lagoon nitrification and extended aeration.
The second option, post-lagoon nitrification is listed as the preferred option for several reasons, the consultants explained, including:
– best ranking for technical performance among the alternatives evaluated;
– provides reliable protection of the environment;
– little to no impacts on noise, air or odour or other nuisances; and
– lower estimated capital and operating costs than other alternatives.
A number of alternative proposals for discharging effluent from the facility are also evaluated in the study, including:
– continuous effluent discharge;
– expansion of the current effluent discharge window; and
– the current discharge program with the addition of a spray irrigation program.
The consultants are recommending the second option, expansion of the current effluent discharge window. Gaudet said the preference was based on discussions with the Ministry of Environment and Grand River Conservation Authority indicating expanded discharge is possible based on the river’s flow and assimilative capacity.
Option three involving spray irrigation, the study notes, does not allow flexibility for additional discharge into the river, presents additional operational challenges and would require additional environmental monitoring.
A proposal to divert wastewater normally released into the Conestogo River for irrigation had been touted as a creative potential solution to the township’s capacity woes.
Dr. Eric Lyons of the University of Guelph had been working with a local ad hoc committee on the proposal, which originally grew out of discussions with Glenavalind officials, who have proposed a subdivision and golf course development in Drayton.
“We do see some challenges to that alternative. In terms of cost perspective and some operational issues it would be more challenging for the township, therefore we are not recommending moving forward with that option,” said Gaudet.
The study also points out the continuous discharge option may not be practical because the MOE and GRCA are not inclined to permit discharge during the summer months.
