Stantec retained HGC Engineering to undertake an Acoustic Assessment of the Brockville Water Pollution Control Centre (WPCC) facility in Brockville, Ontario. The study was required to support an application to the Ministry of Environment (MOE) for a Certificate of Approval (Air & Noise).
The assessment considered all current operable sound sources, as well as several proposed new sources that would be part of a planned upgrade of the Centre to a secondary treatment facility.
Sound level measurements of the existing sources were conducted at the facility while sound emissions from proposed new sources were based on manufacturer’s data or assumed based on measurements of similar equipment conducted by HGC Engineering for past projects. The source sound levels were used as input to a predictive acoustical model to quantify the environmental sound emissions associated with the facility. Acoustic assessment criteria were established in accordance with the sound level limits in MOE guideline NPC-205 and used to assess the sound emissions of the facility.
The lands surrounding the facility are a mixture of institutional, commercial and residential uses. Four key receptors had been chosen to represent the nearest sound sensitive receptors. The nearest residential dwellings are homes on residentially zoned lands approximately 50 metres east and southeast of the facility. The assessment also considered two nursing homes, approximately 110 metres west and 50 metres northeast (of the subject facility on lands designated for institutional uses.
During the site visit by HGC Engineering background sound in the vicinity of the facility was dominated by traffic noise on County Road 2. The existing operations of the Brockville WPCC facility were audible in the vicinity of the nearest points of reception. The area is best characterized as a “Class 2” semi-urban area, under MOE noise assessment guidelines.
The Brockville WPCC facility operates 24 hours per day, 7 days per week. The primary sound sources at the facility prior to upgrade included a number of open doors and windows as well as several building exhausts.
This proposed upgrade would include the addition of an operations centre, several aeration tanks and secondary clarifiers, as well as a WAS/RAS pump building and a UV building. Acoustically non-negligible sound sources associated also included a 1000 kW emergency generator, as well as air handling units and building exhausts.
Non Negligible Sound Sources (existing and proposed):
- General Building Exhausts
- Building Openings
- Air Handling Units
- Standby Emergency Generator
- Blower Room
- Flare Stack
- Trucking Activities
The measurements and analysis indicated that, with combustion exhaust and ventilation silencers for the proposed emergency generator and an acoustical barrier for a proposed rooftop air handling unit, as recommended, the sound emissions of the facility would be within the applicable sound level limits as set out in MOE guideline NPC-205 during normal predictable worst case operations at the nearest points of reception.
Acoustical Engineering Services Included:
- Conducted detailed acoustical assessment of existing and proposed operations.
- Conducted an acoustic audit of existing operations.
- Developed noise control recommendations for new sources.