Local Communities Struggle with the Challenge of Treating Septage
- Saturday, April 16, 2011
The majority of citizens in the Ottawa-Gatineau area live in dwellings which are serviced by municipal wastewater infrastructure – domestic wastewater is transported through a network of pipes and sewers to a wastewater treatment plant, where it is treated and harmful contaminants are removed before the effluent (the treated water) is returned to the river. For residents of rural areas, however, wastewater infrastructure consists of individual septic systems which are maintained, operated and paid for by the property owners themselves.
The way in which septic systems are able to treat domestic wastewater is fairly straightforward. The wastewater flows into the septic tank in which solid, heavier materials are allowed time to settle out of the wastewater, and the water containing the remaining lighter materials and contaminants passes out of the tank and into what is called the leaching bed. The leaching bed, which is essentially a handful of perforated underground pipes, allows the wastewater to slowly leach through the soil, where naturally occurring bacteria and other organisms remove the remaining contaminants and return the quality of the effluent back to an acceptable level for re-introduction to our natural ecosystems.
One of the main tasks associated with the operation of a septic system is having the septic tank emptied of the solid material which accumulates as more and more wastewater passes through the system. This solid material is called septage, and is typically removed every several years. Once it is pumped out of the septic tank, it has to be transported to a wastewater treatment facility to be dewatered, treated and properly disposed of.
In the fall of 2010, rural residents of the MRC-des-Collines-de-l’Outaouais, a collection of 7 Québec municipalities in the Outaouais region, were faced with a significant challenge in the treatment and disposal of their septage. Previously, septage from the region was transported to the wastewater treatment facility in the City of Gatineau for treatment, but given the overwhelming pressure being put on this facility by the large volume of wastewater entering the municipal wastewater system, the City decided to stop accepting waste from areas outside of the city limits. In response to this challenge, the MRC engaged a consulting firm, CIMA+, in helping them develop plans to construct a new septage treatment facility which would treat septage from all 7 of the MRC municipalities.
As plans for the project unfolded and were made publicly available, it became evident that there were a number of issues with the facility and treatment process being proposed by CIMA+ which, if left unaddressed, would pose a significant threat to the health and safety of both the aquatic ecosystems of the Gatineau River as well as the local communities who use the river. Some of the overarching concerns with the project relate to the lack of public involvement in the decision-making process, problematic site selection, the complete lack of a review of cumulative effects relevant to the project, poor assessment of the capacity of the proposed facility to treat all contaminants, chemicals and toxins contained in septage, and a flawed assessment of the “dilution factor” of the Gatineau River.
The question then becomes – what can be done to address these concerns? Recommendations include having the province collect and publish water quality data for the Gatineau River, which should include the total loading of pollutants from all sources; establishing precautionary Effluent Discharge Objectives for the proposed facility which take into consideration local uses of the river and seasonal low flows; getting provincial support in upgrading the City of Gatineau’s wastewater treatment facility to support the City’s own wastewater treatment needs as well as the surrounding region’s needs; commissioning a new feasibility study for the project; exploring and evaluating short-term solutions; and establishing a committee of independent experts and representatives of local and regional interest groups that will promote a collaborative, multi-stakeholder decision-making process.
Ottawa Riverkeeper, Friends of the Gatineau River and Citizens for the Protection of the Gatineau River have written a joint position paper on this issue to not only inform the public of our take on the subject, but to also put forth these recommendations to the decision-makers involved in this project that will help to ensure that the waters of the Gatineau River remain swimmable, drinkable and fishable for future generations.
To read the full list of community concerns and recommendations for moving forward to find an acceptable solution for septage treatment in the region, click here.
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