Watershed groups urge municipalities to curb road salt after rise in chloride levels

Members of the Little Lehigh Watershed Stewards and the Pennsylvania Road Salt Action Working Group presented data and recommended steps to reduce road salt use at a Northampton County meeting, warning that chloride from de-icing is accumulating in groundwater and local streams and poses risks to aquatic life, drinking water and infrastructure.

Jennifer Latsko, a presenter from the PA Master Watershed Steward program, said researchers started testing chloride levels after finding elevated concentrations in the Little Lehigh Creek. "It only takes 1 teaspoon of salt to permanently pollute 5 gallons of water," Latsko said, and she noted that chloride that enters groundwater “builds up and gradually accumulates over time.”

The presenters said local monitoring by the Lehigh County Authority shows average chloride concentrations at a drinking-water intake have more than doubled over roughly two decades. They cited ecological research showing that many aquatic invertebrates used as stream-health indicators decline well below 50 milligrams per liter of chloride and that the U.S. Environmental Protection Agency’s 1988 screening number is 230 mg/L.

Mary Rooney, president of the Little Lehigh Watershed Stewards and founding member of the PA Road Salt Action Working Group, told officials the group is promoting practical changes rather than a ban on salt. "We're not saying don't salt. We're saying use the right amount of salt, at the right time in the right place," Rooney said, adding that groundwater residence times mean current inputs will influence water quality for years.

Presenters summarized municipal and contractor best management practices (BMPs) and the reductions those practices can produce: brining (applied liquid salt) can reduce salt use by as much as 75 percent; pre-wetting rock salt can reduce usage by roughly 30 percent; calibrating spreaders can reduce application by about 50 percent; and segmented plow blades improve scraping and reduce repeat passes. They also cited PennDOT’s recommended salt application rate of 100 to 300 pounds per lane-mile and said some municipalities are applying far more—sometimes over 1,000 pounds per lane-mile.

The group flagged nonroad sources and storage as concerns: a New Hampshire study they cited attributed about 50 percent of chloride loading to parking lots (private contractors), with municipal roads, state roads and salt piles contributing additional shares. Presenters said roughly 40 percent of applied chloride can infiltrate to groundwater, later returning to streams and drinking-water intakes.

Rooney described outreach plans for the Lehigh Valley and statewide efforts, including an open-house idea where municipal maintenance staff can share hands-on BMP experience, a central resource page of presentation materials, and coordination with PennDOT training. She noted an existing model in New Hampshire—Green Snow Pro—that includes voluntary contractor certification and documentation that can reduce liability concerns.

Audience members and a contractor at the meeting raised liability as a central practical constraint. One contractor described pressure from clients and insurers to apply salt preemptively to reduce slip-and-fall risk. Rooney and Latsko responded that better documentation of decisions and amounts applied, plus voluntary certification programs, can protect contractors and encourage consistent, documented BMP use.

The presenters asked Northampton County officials and municipal leaders to help publicize training and open-house events, introduce them to municipalities and contractors that already use BMPs, and consider grant or cost-share options for equipment upgrades.

No formal county action or vote on policy was recorded during the presentation; presenters asked for support and partnership. The group said a separate house bill under discussion would create a state best-practices manual and examine training, but they did not provide bill number or details during the meeting.

The presentation materials and a longer summary are posted on the Little Lehigh Watershed Stewards website; Rooney and Latsko provided contact emails for follow-up and offered to work with county staff on outreach and scheduling for fall open-house demonstrations.