Our take: You read, you decide
The following article was submitted to The Baltimore Post by The Green Towson Alliance. This is the second in a series of articles dealing with this continuing sewage problem.
The Baltimore Post spotlight on Development Dilemma: Seeping, Smelly Sewage first reported on October 6th will resume with the sewerage issues provided from the GTA study with supplemental information from a study investigator. This installment provides DPW data in context for “flushing out” questions and issues.
DPW is planning to install a Towson Run relief sewer to accommodate increased flows from Towson Row, Towson University, and other new development. GTA has requested, but not received, studies to support the need for this new line and to describe the environmental impacts of its construction. The portion of Towson Run that is downstream of Charles Street and drains down to Bellona Avenue contains 21 pipe sections. In dry weather, DPW data states that:
- Two pipes use less than 30% of capacity
- Fifteen pipes use between 30-40% of capacity, and
- Four pipes use between 40-50% of capacity
Under wet weather conditions (DPW sent data for 20-year/24-hour storms to justify relief sewer and color-coded maps showing problematic pipes), when there is stormwater infiltration and inflow (I&I) into the pipes, the DPW data states that:
- Ten pipes would use less than 90% of capacity
- Four pipes would use between 90-105% of capacity
- Five pipes would use between 106-118% of capacity, and
- Two pipes would use between 146-155% of capacity
The communities ask why a relief line is needed, if I&I are properly addressed? Concerns are construction will disrupt traffic, result in removal of many trees, damage wetlands and floodplains, and require access to private properties. The only meaningful information that has been shared with GTA to explain why a relief sewer is needed are DPW wet weather pipe capacity tables that do not seem to be consistently applied downstream in Lake Roland and in the Upper Jones Falls.
Based on County information, three existing sewer lines, Towson Run, Roland Run, and Upper Jones Falls join at the northern end of Lake Roland and flow through a 60-year- old, 3000 foot, 42-inch sewer line directly under the lake. Flows from that pipe continue into the City’s Jones Falls interceptor where the City routinely releases millions of gallons of raw sewage during wet weather events into Jones Falls (structured overflows). The City reports roughly one-half of all its sewage originates in the County.
DPW supplied data indicated that the Lake Roland interceptor would be 144% of capacity during wet weather events. The immediate downstream pipe in the park would be 156% of capacity (and one pipe three sections downstream would be 456%). The GTA analysis indicates significant I&I entering the system, and pipes overloaded to such a degree that raw sewage must be spilling out of the system somewhere or must be backing up into feeder sewer lines. Deficient manholes in Lake Roland Park were documented in a GTA field study, and water samples/health grades of “F” from the lake and its tributaries show the presence of fecal contamination.
In addition to the planned Towson Run relief sewer, GTA learned that other relief sewers are planned for the Upper Jones Falls to remedy certain bottlenecks that need to be accommodated from current flows plus additional flows from proposed development. Since the Upper Jones Falls Sewer flows into the Lake Roland interceptor and then downstream into Jones Falls and City, this portends still higher flows into those pipes.
GTA analysis of DPW data indicates numerous overloaded pipe sections along the Upper Jones Falls interceptor. There are 10 pipe sections that lead to the junction box and manhole where the three interceptors join. Nine of those pipes have wet weather capacities well over 100%
- Three pipes would use between 111-119% of capacities
- Five pipes would use between 164-197% of capacities, and
- One pipe would uses 589% of its capacity
DPW stated the capacities data above did not include projections for Towson Row and University, and other growth. GTA could find no disclosures about any of this under 2002 and 2005 Consent Decrees reports, Triennial Reviews of Water Supply and Sewerage Plans, and Basic Services Maps showing areas of sewer concerns and deficiencies.
Raw sewage in our waters is unacceptable. Why is all this not a concern?