Collection system capacity will continue to be of paramount importance to municipalities. Increasing population growth, peak wet weather infiltration/inflow and pipeline deterioration all affect the ability of the collection system to properly transport wastewater flow. Inadequate capacity results in Sanitary Sewer Overflows (SSOs) across the country with subsequent Federal and State regulatory actions.
The importance of system capacity has been demonstrated in the new CMOM (Capacity, Management, Operation and Maintenance) regulations promulgated by EPA. Under the CMOM program each municipality must evaluate system capacity and develop an assessment of needs that ensure adequate capacity is provided now and into the future. Flow monitoring at strategic locations within the collection system will document current capacity utilized and identify potential bottlenecks or restrictions that reduce system capacity.
Proper interpretation of flow data can identify areas where line capacity has been reduced due to debris, roots, broken pipe or other hydraulic restrictions. In many cases we find SSOs are due to inadequate capacity resulting from hydraulic bottlenecks that can be easily rectified. Obtaining and interpreting actual hydraulic data will provide the information necessary to address the assessment of collection system capacity.