In late July, Lehigh County communities promised they would spend at least another $30 million over the next few years plugging leaks in a regional sewer system.
The record rainfall from August to year’s end has illustrated the urgency.
Nearly 14 million gallons of untreated sewage spilled into the Little Lehigh Creek at the Kline’s Island wastewater treatment plant in Allentown during storms in August and November. Smaller but abnormally prolonged overflows from manholes in the Trexlertown area compelled the Lehigh County Authority to declare an emergency in late November to speed up sewer investigations and repairs.
LCA estimates the ongoing emergency work in the Trexlertown area will cost more than $800,000. It’s also planning a roughly $13 million project to address a sewage transportation bottleneck in the main artery, running near Trexlertown Road from the Route 222 bypass in Upper Macungie Township to Spring Creek Road in Lower Macungie Township.
More sewage spilled in 2018 than any other year since the U.S. Environmental Protection Agency ordered Allentown and every other municipality sending sewage to Kline’s Island to eliminate the overflows in 2009.
The EPA has not yet responded to the joint submission this summer of a “Regional Flow Management Strategy,” an outline of each community’s plan to identify and fix leaky pipes. But in late December, state Department of Environmental Protection officials who reviewed the plan asked for more details, including firmer timelines and deadlines for flow measurement projects and major repairs. The communities must respond by March 29.
State regulators also issued a notice of violation in October related to the untreated sewage discharges at the Allentown treatment plant and the overflows in Trexlertown. No fine was assessed, department spokeswoman Colleen Connolly said.
About 65 inches of rain fell in the Lehigh Valley in 2018, making it the third wettest year on record. Nineteen storms exceeding 1 inch caused groundwater levels to rebound from dangerous lows two years ago to their highest point in a decade.
More than 900 miles of sanitary sewer pipelines lead to the Kline’s Island plant, which is on the Little Lehigh Creek near its confluence with the Lehigh River. The system is designed to handle only raw sewage. But during heavy rains, stormwater trespasses into the system, overwhelming it. That’s when sewage spills into waterways.
Because of growth on the western end of the region, the major sewer line in Trexlertown handles relatively close to its maximum capacity on dry days. That doesn’t leave much of a cushion on wet days when stormwater infiltrates — or when groundwater levels are as high as they are now.
Late last year, the stormwater infiltration in Trexlertown was so intense sewage flowed backwards to the authority’s pretreatment plant in Fogelsville. During its emergency operations, LCA held back sewage in a “flow equalization basin” so it could identify major sources of leaks as well as significant debris — including big pieces of broken pipe from municipal systems that feed into primary sewer mains.
While the emergency work is costly, authority CEO Liesel Gross said it could save money in the long run. That’s because conducting leak investigations is a lot easier when stormwater is gushing through breaches than during dry conditions. LCA had planned to examine this section of the sewer during dry conditions later this year.
LCA is also hoping to investigate the next section of the main sewer line running along the Little Lehigh Creek in Lower Macungie’s Ancient Oaks neighborhood, but persistent flooding has made this challenging, Gross said.
Authority officials took state regulators on a tour of Trexlertown operations in December to explain the challenges and demonstrate their sense of urgency, Gross wrote in a memo to the authority’s Board of Directors in December.
The DEP believes the work to limit sewage discharges in the area is progressing, Connolly said Tuesday.
Long-term plans
Over the next month, the authority board will review a proposed budget for capital projects over the next five years. That likely includes the Trexlertown Interceptor, a two-mile-long, 24-inch pipe running parallel to the existing clogged interceptor that will share the sewage load flowing from much of Upper Macungie. As an alternative, the authority is considering a pumping station next to its pretreatment plant.
If LCA decides to build the parallel sewer pipe, it will begin acquiring right of way later this year and complete construction in 2023.
LCA also will install temporary flow meters through Upper Macungie and Lower Macungie sewers for nine months to collect data on the leak repairs and to determine if additional sewer capacity is needed. It also is renovating the Park Pump Station in Allentown to prevent daily overflows in city sewer mains.
DEP questions
Each municipality that sends sewage to Kline’s Island explained to state and federal regulators in the late July report how it plans to keep stormwater out of the sewer system. The communities compiled a summary on shared projects, such as testing and potentially updating meters used to determine how much sewage each municipality is contributing to the system during both dry and wet periods.
In an eight-page response, DEP environmental engineer James Ridgik asked for a firmer commitment on when the communities will complete the meter evaluation and upgrade, emphasizing that data is imperative to better understanding sewage flow patterns.
Postponing this process beyond 2019 “is not acceptable,” he wrote.
He also asked for more information on municipalities’ approach to inspecting the private pipes connecting homes to the sewer network.
Municipal representatives are meeting at the end of January to work on responses to the DEP.