Finding Inflo’: A Public-Private Animated Production

When the City of Lawrence, Massachusetts watched their average daily dry-weather wastewater flow contribution double between December 2013 and May 2014, they assumed there had to be a mistake. When notified that their flow contribution was accurate, the city undertook a widespread effort to investigate, locate, negotiate, and abate what turned out to be a single multimillion gallon, dry weather inflow that had the potential to increase annual sewer treatment costs by $500,000 per year.There were a variety of challenges in discovering the source of the problem. A thorough Sanitary Sewer Evaluation Survey was at the heart of the effort to pinpoint the issue. Unfortunately, in this instance, the engineering was the easy part. After confirming the system defect, the City faced the challenge of dealing with multiple stakeholders, confirming asset ownership, assigning responsibility, abating the inflow source and ultimately beginning to modify a 40-year-old community flow share agreement.