Action | Action to Adopt Regulations for Alternative Onsite Sewage Systems |
Stage | Proposed |
Comment Period | Ended on 2/4/2011 |
Dilution of effluent,, as a method to meet proposed TN limitations, should not be prohibited for Large AOSS for the following reasons:
Project Area Boundary is analogous to the mizing zone concept used to model effluent limitations for wastewater treatment plant discharges. Selection of the Project Area should be a design element allowing the engineer to increase the dedeciated surface area beyond minimum requirements.
The ability for owner/client to evaluate cost-benefit analysis of wastewater treatment versus land allocation as a method to meet proposed TN/TP standards is lost if there is no benefit to increasing the Project Area above that required by the regulations.
Atmosheric-precipitation TN/TP inputs are negligible; mixing of the unpolluted water with polluted water is a long established method to meet onsite effluent TN limitations. The ability to tailor in-ground dispersal system geometry to maximize Project Area dilution inputs is lost if no dilution credit is granted. If this option is lost, then the only option is increaseing treatment plant size.
Dedicating land to Project Area as the added benefit of reducing impervious areas, preserving natural resources, fallow land recover, potential to support EPA/DEQ Water Reuse and Recyle programs and supports GREEN development concepts.