I support the proposal with…

I support the proposal with appropriate design to ensure that the drinking water aquifer is protected from nitrate. Through a combination of treatment to reduce total inorganic nitrogen and dilution from infiltration of precipitation over the entire property, the concentration of total inorganic nitrogen entering the aquifer should be 10 mg/L or less. The Ontario Building Code does not recognize nitrogen removing technologies. In the long-term, it would be helpful if the OBC included nitrogen and phosphorus (for properties near sensitive lakes) removal classifications and included sampling for nitrogen and phosphorus. The OBC does not have language to require sampling for nitrogen in the effluent, but the system still needs to be designed to be capable of removing the required % of nitrogen for that property. Treatment systems with recirculation to an anoxic volume typically offer 50% or more total nitrogen removal. Technologies exist that add steps after Level IV treatment to denitrify the effluent to provide 75% or more total nitrogen removal (wood chip treatment wetland or a chemically based reaction step). I recommend that a P.Eng. sign off on designs submitted where total property flow is over 10,000 L/d and be allowed to choose technologies that may not be BNQ certified for Level IV treatment of residential sewage but are technologies routinely approved by the MECP for ECAs. These farms, typically greenhouses, will tend to have help houses on the perimeter of the greenhouses and therefore cannot put each individual septic system at the centre of an area to dilute each system's effluent. It would be more practical to allow the individual systems to be put anywhere on the property and assess the impact to groundwater using the entire property for dilution. This is in contrast to the plume approach required for MECP ECAs (chapter 22 of MOE 2008 wastewater guideline), but is similar to the approach used for MOE D-5-4. As with D-5-4, the concentration target to the aquifer would be 10 mg/L nitrate, as opposed to applying the Reasonable Use Guideline that can require as low as 2.5 mg/L total inorganic nitrogen. It can take 18 months to obtain an ECA. As a faster alternative, the authority having jurisdiction can require a P.Eng. to calculate the nitrogen impact to the aquifer, include treatment with the required nitrogen removal and sign off on the design. The P.Eng. could also sign a commitment to inspect the system if the authority having jurisdiction felt they were not familiar with the nitrogen removal technology.