Water Service - Wastewater Treatment

New Tecumseth TP Offset

Client:

Town of New Tecumseth
Location:

New Tecumseth, ON
Budget:

$50,000
Key Features:

Model development, evaluation of multiple scenarios and recommendations of flows and limits for each wastewater treatment plant

The Town of New Tecumseth owns and operates three wastewater treatment plants (WWTP’s). The WWTP’s include the Tottenham WWTP, servicing the community of Tottenham, the Regional WWTP, servicing a portion of Alliston and the town of Beeton, and the Alliston WWTP, servicing the remainder of Alliston. The Town of New Tecumseth is expecting to experience significant growth. To ensure sufficient wastewater treatment capacity, a Class Environmental Assessment (EA) was completed in 2005 by another consultant. A key recommendation was the decommissioning of the Tottenham WWTP and pumping the effluent to the Regional WWTP. However, significant performance improvements were subsequently achieved at the Tottenham WWTP, and because of the high capital cost of the preferred alternative identified in the 2005, the Town commenced an update of the Class EA including review of the preferred alternative selected in 2005. A key element was an updated assessment of the impacts of various options on surface water quality.


All three WWTP’s discharge into tributaries of the Nottawasaga River, or into the Nottawasaga River directly. To assess water quality impacts associated with regional wastewater flows, it was necessary to examine all three facilities under a common framework. Therefore a custom water quality model was developed for this purpose. The model was constructed using Microsoft Excel™ and allowed for rapid assessment of a wide variety of WWTP scenarios.  The model accounts for the fact that downstream flow and quality are to a large extent determined by upstream characteristics.

 

 

Project Gallery - Click an image to enlarge.

 

The simulations showed that the capacity of the Regional WWTP could be increased without significantly affecting the water quality in the Nottawasaga River. Flows were expected to remain within the current CofA limits for the Alliston WWTP; it was recommended that the ammonia effluent limit for summer should be re-evaluated.  It was also concluded that leaving the Tottenham WWTP online was a feasible option. A new Tottenham WWTP would be capable of maintaining effluent concentrations and loads that would not significantly degrade the receiver; further the additional flows discharged could be of value to downstream users (mostly irrigation) who are often concerned with the low flows observed in Beeton Creek.


Concerns about increased TP loading to Beeton Creek were addressed by XCG by investigating the potential for TP load offsets.  Offsets reviewed included stormwater retrofits for existing development or improvement to existing stormwater facilities, crop management practices, manure storage and livestock fencing.


The final proposed TP offsetting scheme incorporated stormwater management for sizeable areas that currently receive no treatment, by constructing new or modified stormwater facilities.  The certainty of this TP offset is high as the stormwater facilities will be regulated by the MOE and owned and operated by the Town.  The other major component was a program for improved manure management on private farms.  This component would require an outreach program (led by the Town and the NVCA) as well as funding (to be provided by the town). MOE reviewed the proposed offsetting scheme and found that it met their expectations. As a result, the Tottenham WWTP will remain online and the TP offsetting will be incorporated into the CofA.