Road Salt Contamination Claims: Technical and Legal Issues

(from Maine Townsman, November 2004)
By Keith Taylor, CG, Stratex, LLC, Gregory Cunningham, Esq., Bernstein Shur Sawyer & Nelson

Even during low snow winters such as our most recent one, Maine municipalities depend on salt to keep their roads safe for the public. Some have their own salt storage piles at the public works garage, while others use a private contractor to supply and/or treat the roads. The salt is usually mixed with sand and liberally spread on trouble spots such as hills and at busy intersections. Slick roads are particularly a problem in the more rural communities where the roads still have sharp curves and steep slopes inherited from the old horse and wagon paths of the past. Unfortunately, these rural areas are also known for their reliance on private water supply wells. Most municipalities are aware that salt leaching from storage piles can contaminate wells, but road runoff containing salt is also the source of contamination for many private wells.

Legal claims by citizens against Maine municipalities for salt-contaminated wells are much more common than you might think. A Maine statute specifically addresses the process for filing such claims and describes the responsibilities of the municipality. These claims can cost thousands of dollars to simply assess their validity, even if the claim never goes to court. If the municipality is responsible, the costs for a new well, treatment, and/or other damages can reach into the tens of thousands of dollars. It may be too late to avoid a claim if salt contaminated-ground water is already heading toward someone’s well. However, this article should help you understand why the contamination occurs, how to deal with homeowner’s claims, and what your legal responsibilities are.

Road Salt Contamination

The most well-known source of salt in ground water is salt storage piles. In the past, road salt was usually stored in large uncovered piles. Rain and snow falling on the pile dissolves the salt and carries it into the ground, where it enters the water table. Continued leaching of salt through time produces a “plume” of salty water that migrates away from the salt pile in the direction of ground water flow, which usually follows the slope of the land. If the migrating plume reaches a well, or is drawn toward the well because of pumping, the well becomes contaminated. These contamination plumes can be hundreds of feet long and therefore may contaminate a well for many years even after the salt pile is covered or removed.

Because of the risk these salt piles posed to public and private ground water supplies, the Maine DEP completed a risk rating in 1986 of all known public and private road salt storage areas. As many readers may know, this priority list was to be used by the Maine DOT to direct funds for the construction of salt storage buildings. However, fund shortages prevented many buildings from being constructed, so the DEP updated the list in 2000 and identified a subset of salt piles that posed the greatest risk to ground water supplies. These high-risk sites remain eligible for funding from the DOT.

Despite the construction of many new salt storage buildings, contamination still occurs from road salt that remains in the ground from previously uncovered salt storage piles, and from the direct application of salt to roads. Salt contamination from road applications is more difficult to predict and assess than from salt piles since the pathway of the salt to the well may not be obvious. In the simplest case, this type of contamination occurs when the road grade or drainage system channels the salty meltwater directly toward the well. However, road salt contamination can sometimes occur where this type of surface flow is not evident.

The most common indicators of salt contamination are taste and corrosion or staining of plumbing fixtures. Other indicators of salt contamination include corrosion of water heater components and well pumps, stressed vegetation in the yard, and unhealthy houseplants. Homeowners typically will contact a local laboratory and have a sample tested for chloride and sodium. For uncontaminated wells in Maine, the average concentrations of chloride and sodium are 29 and 13 milligrams per liter (mg/L), respectively. Highly contaminated wells can show chloride and sodium concentrations between 500 and 1,000 mg/L. Elevated chloride in drinking water does not represent a health risk, but a Federal Secondary Drinking Water Standard of 250 mg/L is in place because of the taste and corrosion problems. Elevated sodium concentrations can pose a risk to those on a low sodium diet due to high blood pressure or other health problems, therefore the State has established a Maximum Exposure Guideline of 20 mg/L. There is no Federal drinking water standard for sodium.

Other Sources of Salt Contamination

It is important to note that there are other possible sources of salt contamination in a well. Modern seawater intrusion can contaminate a well near the coastline. Trapped ancient seawater has been documented in Maine as a source of salty water in private wells. Septic system leachfield discharges can produce localized plumes of ground water high in salt under certain conditions. A detailed analysis of water quality, well construction, and site geology are needed to determine if any of these or any other alternative sources are the cause of elevated salt concentrations in a well.

Legal Claims and Responsibilities of a Municipality

Municipalities in Maine should be familiar with the specific statutory provisions that outline both the procedure for addressing road salt contamination claims and that define the scope of any liability arising from such contamination.

In 1987 the Legislature enacted 23 M.R.S.A. § 3659, which creates a cause of action for any landowner whose private water supply located on his or her land has been “destroyed or rendered unfit for human consumption” by a municipality or other political subdivision. Arguably the impacts contemplated by section 3659 can include road salt contamination of private water supplies. A municipality is susceptible to liability under this provision if it has damaged a private water supply as a result of its construction or maintenance of a public highway under the municipality’s jurisdiction. The State is also potentially liable for its acts of construction and maintenance that impact private water supplies located on land adjacent to state or state-aid highways, pursuant to a separate statutory provision. See 23 M.R.S.A. § 652. As a result, any claim must be analyzed closely to determine whether it involves either actions of the municipality, alleges actions taken on municipal roads, or both.

Section 3659 places limitations on both the scope of liability and the damages that a municipality may confront in a road salt contamination case. Any damages claimed must be based on the lesser of (a) the difference between the fair market value of the property before the private water supply was impacted and its fair market value thereafter or (b) the cost to cure any damage to the private water supply. A municipality will not be liable if the private water supply is located within the road right of way, if the location of the private water supply does not provide for adequate surface drainage (unless the surface drainage problems were as a result of the municipality’s actions in constructing or maintaining the road), or if the private water supply was contaminated by another source prior to the municipality’s work on the road.

Road salt contamination claims have their own notice and settlement procedures as well. Because the cause of action created by section 3659 is a statutory exception to the Maine Tort Claims Act, municipalities must be mindful that the less common road salt contamination claim procedure must be followed. The statute requires that the landowner apply in writing to the municipality for a determination of the cause of the unfit private water supply and an assessment of damages resulting from it. This application must be filed within two years after completion of the roadwork at issue and must set forth specific information relative to the private land at issue and its owner, and must describe both the damage and the perceived cause of that damage. The triggering of this limitations period for filing claims is the date of the completion of the work as documented in the records of the municipality. The municipality is obligated to respond within 90 days of receipt of the application. A timely response to the claim is critical, as a one-year statute of limitations for filing a claim in superior court begins to run as of the municipality’s response. This response must either deny responsibility or propose an offer of settlement. The statute suggests that the municipality consider remedies that include replacing the water supply (as well as any piping, tanks, pumps, heating systems or related fixtures that were impacted), repairing the damage to the water supply, or offering to either purchase the affected property or to pay a monetary settlement.

Should the municipality deny responsibility, the landowner’s recourse is to file suit against the municipality in the superior court of the county in which the land is located within one year after receiving the municipality’s response. A court-appointed referee thereafter hears and rules upon the landowner’s claims.

How to Assess Contamination Claims

It is the responsibility of the claimant to demonstrate that the municipality is responsible for road salt contamination of their well. Most claims are based on one or more laboratory reports provided by the homeowner. However, as discussed earlier, there are a variety of mechanisms for wells to become contaminated and different sources for salt contamination. Before assuming responsibility, a municipality should seek the advice of an environmental professional experienced in ground water contamination. Additional sampling or other investigations may be necessary to assess the claim and evaluate the possible remedies.

Options for Settling Claims

Road salt contamination in ground water can take years to dissipate even after the source of contamination has been removed. Removing the contaminated ground water would be very expensive and impractical. Therefore, if a municipality assumes responsibility, and assuming public water is not available in the area, there are three primary options for settling road salt contamination claims: 1) modifying the existing well, 2) installing a new well, or 3) installing a water treatment system. In some cases, an existing well can be modified to seal off the water-bearing fractures in the rock that are the source of the salt. However, geologic investigations may be necessary to determine if this approach is feasible. A new well is the simplest solution since it represents a one-time cost for the municipality. One possible complication is if there isn’t a suitable location on the property for a new well. This situation can arise when the salt contamination is found to be present throughout the property, or setback limitations are present due to property lines or septic systems. An easement on an adjacent property may be necessary under these circumstances. Installation of a water treatment system is always feasible but is expensive. Annual maintenance and electricity costs will be significant and represent a long-term responsibility of the municipality.


Road salt contamination claims against municipalities are more common in Maine than you may think. Despite the covering of many salt piles, groundwater contamination may still exist or could be generated from road salting. However, other sources of salt contamination in wells do exist. Salt contamination generally does not present a health threat, but can result in damaged plumbing fixtures and make the water unusable. A Maine statute outlines the procedures for making claims against a municipality and how a municipality is to respond. Because the legal and technical costs for settling claims can be high, Maine municipalities should be familiar with the technical and legal implications of road salt contamination claims.