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Source Water Assessment and Protection Program

Storm drain stencil

Ohio's Source Water Assessment and Protection (SWAP) program assists communities with protecting their sources of drinking water (streams, lakes and aquifers) from contamination. Also known as "Drinking Water Source Protection" and "Wellhead Protection," the SWAP program addresses over 4,800 public water systems in Ohio and does not address private residential water systems.

Although Ohio's public water systems treat their drinking water to meet health-based standards, treatment is expensive and may not address every kind of contaminant. By taking steps to avoid chemical spills in the areas surrounding a well field or upstream from a surface water intake, a community can help reduce the costs of their water and better ensure a safe and high-quality supply of drinking water.

Endorsed Drinking Water Source Protection Plans

Municipal public water systems develop a written plan that addresses sources of contamination that have a potential to impact their source water. Non-municipal public water systems complete a checklist that is tailored to the types of potential contaminant sources identified in their protection area. Protection plans and checklists are submitted to Ohio EPA for review and endorsement.

Overview and Frequently Asked Questions

What is Drinking Water Source Protection?

For each public water system, Drinking Water Source Protection involves two phases: assessment and protection.

Example SWAP areaAssessment is determining the area around the public water system's well(s) or intake(s) that will be the focus of protection (delineation), and then listing all of the facilities or activities within that area that could potentially release chemicals that would contaminate the source water (inventory). Based on the delineation, inventory and the local geology, the likelihood of the source water becoming contaminated is determined (susceptibility analysis). Since 2001, Ohio EPA staff have provided public water systems with assessments; however, some public water systems prefer to hire a hydrogeologic consulting firm to complete their assessment.

Drinking Water Source Protection road sign

Protection refers to the activities undertaken by the public water supplier and other interested parties to protect the SWAP area. For this purpose, Ohio EPA strongly encourages municipal public water suppliers to form a local planning team and develop a Drinking Water Source Protection Plan.

See "Developing a Drinking Water Source Protection Plan" in the next tab for detailed information on writing a protection plan. 


Where did the SWAP program come from?

The federal Safe Drinking Water Act amendments of 1986 established the Wellhead Protection Program, which required states to administer a source water protection program for their systems using ground water. In 1992, Ohio's Wellhead Protection Program was approved by the U.S. Environmental Protection Agency (U.S. EPA). Administered by Ohio EPA, the program provided guidance and technical assistance to public water systems, who were encouraged to complete assessments and protection plans using their own resources. Ohio EPA staff reviewed the assessments and formally endorsed them, when complete.

In 1996, the Safe Drinking Water Act was amended again. Section 1453 was added, providing states with federal funding to complete source water assessments for their public water systems. At that time, the program was extended to include surface water systems and was renamed "Source Water Protection." Also, an additional piece of information was required in an assessment, a Susceptibility Analysis. Susceptibility is defined as the likelihood that contaminants will impact a public water system's source water(s) at concentrations that would pose a concern. 

It is the intent of Congress that a public water system use the information in their source water assessment to develop a drinking water source protection plan. Ohio EPA convened a Source Water Advisory Group to develop Ohio's Source Water Assessment Program, which was approved by U.S. EPA in 1999. In Ohio, Ohio EPA's Division of Drinking and Ground Waters administers the program.

What's the difference between the Source Water Protection (SWAP) program and the Wellhead Protection (WHP) program?

Source Water Protection ("SWAP") and Wellhead Protection ("WHP") are both national programs designed to help protect our nation’s drinking water. They have the same goal and the same methods, but originated at different times historically, with different scopes. The Wellhead Protection program was created by the 1986 amendments to the Safe Drinking Water Act and focused exclusively on ground water systems. Ten years later, Congress recognized that the program was faltering due to lack of funding. They passed the 1996 amendments to the Safe Drinking Water Act, which extended source water protection to surface water systems and provided funding.

In Ohio, the WHP program is merged into the Ohio SWAP program, which is administered by Ohio EPA. The terms WHP and SWAP are used interchangeably. (In some states, the two programs are kept separate due to state-specific administrative or legal issues.) In Ohio, the differences between the two programs are mostly of historical interest and are summarized below.

Scope: WHP focused exclusively on ground water systems and prioritized large community systems. SWAP extended the program to all public water systems, including surface water systems and non-community systems.

Work focus: The national WHP program provided standards for public water systems to conduct assessments (delineation and inventory of a protection area) and develop a local protection plan. The national SWAP program exclusively addressed assessments.

Funding: National funding was not provided for WHP. For SWAP, a one-time federal grant was awarded for conducting assessments to each state with a U.S. EPA-approved SWAP program. Ohio’s SWAP program was approved in November 1999.

Susceptibility Analysis: The national WHP program did not require susceptibility analyses as part of assessment activities. This requirement was added to the SWAP program. In 2001-2003, Ohio EPA completed susceptibility analyses for all public water systems that had already completed their own assessments under WHP. Public water systems with an endorsed "Wellhead Protection Plan" are considered to meet all the guidelines for a "Protection Plan" under SWAP.

What is a public water system?

Public water systems (PWS) are regulated by the Ohio EPA, Division of Drinking and Ground Waters (Ohio EPA, DDAGW). A public water system is defined as a system that provides water for human consumption to at least 15 service connections or serves an average of at least 25 people for at least 60 days each year. This includes water used for drinking, food preparation, bathing, showering, tooth brushing and dish-washing. Public water systems range in size from large municipalities to small churches and restaurants that rely on a single well. There are three types of public water systems:

City of Lima's Waste Water Treatment Plant Picture of a School Building Non-transient non-community public water system

Community water systems serve at least 15 service connections used by year-round residents or regularly serve at least 25 year-round residents. Examples include cities, mobile home parks and nursing homes. 

Non-transient, non-community systems serve at least 25 of the same persons over six months per year. Examples include schools, hospitals and factories.

Transient, non-community systems serve at least 25 different persons over 60 days per year. Examples include campgrounds, restaurants and gas stations. In addition, drinking water systems associated with agricultural migrant labor camps, as defined by the Ohio Department of Agriculture, are regulated even though they may not meet the minimum number of people or service connections.

Public water systems use either a ground water source or a surface water source, including ground water under the direct influence of surface water. In Ohio, more than 4,800 public water systems serve approximately 11.1 million people daily.

Private water systems are regulated by the Ohio Department of Health. Private water systems are households and small businesses that serve fewer than 25 people per day 60 days out of the year, and are thus not public water systems. Examples include small bed and breakfasts, small day-cares and small churches.

Are there any regulations that apply to SWAP areas?

Yes, there are regulations. Click on the link below for a list of the activities that are prohibited or restricted in drinking water source protection areas:

Are reports written for systems that purchase their water?

Ohio EPA completes assessment reports only for those systems that actually pump water from an aquifer or a surface water body. Any public water system that pumps its own water and then sells it to other public water systems should make copies of the Assessment Report available to the purchasing systems.

What is a Drinking Water Source Protection Plan?

A Drinking Water Source Protection Plan is a locally designed and implemented plan to protect the source of drinking water from contamination at the source. The focus and scope of a protection plan is dependent on the size and type of water system, as discussed below:

Municipal public water systems (serving a political jurisdiction) and investor-owned water companies using ground water: A typical plan addresses (1) educating residents and decision-makers about protecting the source water; (2) including source water concerns in the system's contingency plan; and (3) strategies to reduce the risk posed by specific potential contaminant sources. Monitoring of the raw water may be an additional element. The protection plan may be implemented as a completely voluntary effort or through a local ordinance that would give the jurisdiction the ability to enforce certain measures.

Available Protection Planning Guides for Municipal Ground Water Systems

Non-municipal public water systems (serving mobile home parks, nursing homes, schools, factories, and small businesses) using ground water: When Ohio EPA staff complete a system's assessment report, they attach a checklist that is tailored to the types of potential contaminant sources identified in the system's protection area. The owner/operator is asked to check off strategies that they intend to implement or are already implementing and return the checklist to Ohio EPA. This checklist then becomes the system's protection plan. Some non-municipal systems may want to develop a more comprehensive protection plan. If so, the system may also use the materials developed for municipal systems.

Public water systems using surface water: Most surface water systems serve a large population, and the protection areas are typically many square miles in extent. Ohio EPA currently is developing guidance for these systems on how to develop a drinking water source protection plan. Public water system operators are encouraged to strongly support any watershed planning organizations that are active in the watershed upstream from the water plant's intake.

Available Protection Planning Guide for Surface Water Systems

Which public water systems in Ohio already have an endorsed plan?

Click here for a list of Municipal Systems with Endorsed Protection Plans.

Click here for a list of Non-Municipal Systems with Endorsed Protection Plans.

How can I get involved in Drinking Water Protection Planning for my community?

storm drain stencil telling people not to dumpContact the public water system superintendent and ask if a Drinking Water Source Protection Plan is in place or being developed. If not, you may want to offer your assistance in organizing a protection team in your community. Much of the effort involved is organizational, and anyone with energy and organizational skills can be a valuable resource. A good protection plan will make full use of existing agencies, regulations and volunteer groups to carry out the protective strategies that are chosen. Drinking water sources are vulnerable to contamination that can cause a community significant expense and threaten public health. Water is a shared resource, and individuals, citizen groups and local communities can participate in many activities to help protect their drinking water sources. U.S. EPA provides information on how to learn about source water protection in your area, things you can do to protect your drinking water and steps you can take in source water planning at the community level.

Developing a Drinking Water Source Protection Plan

The following Ohio EPA guidance documents are available for anyone interested in developing a local drinking water source protection plan for their municipal public water system:

Follow the steps below to develop a local Drinking Water Source Protection Plan:  

Step 1. Form a Local Committee

The first step in developing a local source water protection plan is to discuss the idea with the public water supply operator or superintendent and organize a planning committee.

To ensure widespread acceptance and commitment to the protection plan, develop the plan with a group of people representing the diverse viewpoints and local expertise of the community. Participants should include individuals who will play a role in implementing protective strategies, as well as those most likely to be affected by any decisions made (generally people who live, work or own businesses in the protection area). At a minimum, the team should include local decision makers, water supply staff members, and someone with knowledge of emergency response and/or environmental compliance.

In the end, the most successful drinking water protection efforts are those publicized early and often and presented as a community source of pride. These successes can be traced back to the protection team.

Step 1a. Pass a Resolution (optional)

For some communities, the next step is to have the Village or City Council discuss and pass a resolution. This assures the planning group that the local leadership will support their efforts.

Step 2: Review the Drinking Water Source Assessment Report

SWAP reportThe protection team should review the public water system's Drinking Water Source Assessment Report and update the potential contaminant source inventory. Most of the assessment reports were originally written in 2002-2003. If the report has not been updated recently, there may be a number of "potential contaminant sources" that are no longer operating within the drinking water source protection area or new facilities that have located there. Ohio EPA generally will not endorse a protection plan for a drinking water source protection area that has not recently been re-inventoried.

Step 3. Develop Protective Strategies (includes outreach/education, contingency planning for alternative water sources, BMPs addressing potential sources of contamination, and ground water monitoring)

Spill containment around an above ground storage tankThe planning group should prioritize the threats to the source water and decide what types of efforts can be implemented to reduce threats. For endorsement by Ohio EPA, the protection plan must discuss the following types of protective strategies:

  • Public outreach/education
  • Source control strategies
  • Contingency planning for source water contamination
  • Source water monitoring

Public Outreach/Education

Kid's learning about ground water at a local festivalA good education and outreach strategy can have a lot to do with the success of a community's drinking water protection goals. A resident or business owner who understands the importance of protecting their drinking water resources will be more inclined to implement sound management practices, vote for funding to protect the community's drinking water resources or accept the need to implement zoning within the protection area.

Educational programs can be directed at business owners, households, school children, civic organizations, workers or the community at large, depending on which type of potential contaminant source is targeted. Some of the more commonly used educational tools include:

Drinking Water Source Protection Video

Source Control Strategies

Salt storageSource control strategies are actions or techniques that reduce the risk of source water contamination from specific sources within the protection area. A few of the commonly identified strategies include:

  • Source prohibition or restrictions (certain activities cannot occur within a designated area)
  • Design standards (such as berms or secondary containment systems)
  • Specific operating standards (such as periodic inspections, testing, maintenance or reporting requirements)

Most large facilities handling chemicals are regulated by Ohio EPA and other agencies. These facilities may have a Spill Prevention Control and Countermeasures (SPCC) plan and/or a storm water management plan, in addition to various permits. Most of these facilities are required to report periodically to the agencies regulating them, and their reports are usually public information. The planning group should attempt to learn as much as possible about the facilities within the protection area so they can focus their efforts where there are inadequacies.

Environmental regulations that provide special requirements for facilities located within source water protection areas currently are in effect for certain types of landfills, wastewater treatment plants and manure storage facilities, underground storage tanks, concentrated animal feeding operations (CAFO's), brownfield sites and agricultural fields being treated with wastewater.

Contingency Planning for Source Water Contamination

Wastewater Treatment PlantMost public water systems have a contingency plan for emergencies such as power failures and floods, but may provide little instruction for how to react if there is a spill of chemicals within the source water protection area. As part of source water protection planning, the contingency plan should be edited, if necessary, to include such instruction for both short-term and long-term contamination of the source water.

Source Water Monitoring

Ground Water samplingTo be endorsed by Ohio EPA, the protection plan must evaluate the need for a source water monitoring plan. The primary reasons to monitor the source water before it reaches the treatment plant are:

  • Early warning of a contaminant plume
  • Tracking raw water quality trends over time
  • Evaluating the effectiveness of selected protective activities


The need for additional monitoring is greater when:

  • The source water is highly susceptible to contamination.
  • The source water is already contaminated.
  • Existing source water quality data is insufficient.
  • There are potential sources of contamination in the protection area that pose a significant risk to source water.

Guidance Documents for Source Water Monitoring:

Step 4. Decide Implementation Mechanisms (such as ordinances)

Some communities choose to enforce their plan through adoption of a source water protection ordinance that places some restrictions on activities that may occur within the source water protection area. Ohio EPA recommends that, at a minimum, responsibility for periodic updates of the plan be incorporated into the job description or one or more municipal employees.

Chagrin River Watershed Partners Chagrin River Watershed Partners Model OrdinancesOrdinances can be a powerful option for addressing a large number of contaminant sources, and can provide the authority for ongoing enforcement at the local level. Zoning channels future development away from the well field or watershed to a less sensitive area. If the protection area is undeveloped and not zoned, the community can zone it a "natural resource protection area." If the protection area is developed and not zoned, the community may introduce zoning, with recognition that existing development needs to be grandfathered. If the protection area is already zoned, "overlay zoning" may be introduced.

The Chagrin River Watershed Partners in conjunction with local and state agencies has developed a number of model ordinances and reslolutions relate to riparian setbacks, wetland setbacks, storm water management, and erosion and sediment control. Examples of these can be found on the CRWP website: 

Examples of model ordinances for Source Water Protection can be found on U.S. EPA's website: 

Example Ordinances

The following is a list of ordinances that have been enacted by municipalities. For more information, please contact the public water system.

Step 5. Submit the Plan

The Village of Versailles receiving a certificateThe plan should be submitted to Council for their approval and then submitted to Ohio EPA's Source Water Assessment and Protection Program for endorsement. With an endorsed protection plan, the community can receive higher priority for Ohio EPA's low-interest infrastructure loans.

 Funding Sources for Drinking Water Source Protection

Sole Source Aquifers in Ohio

Sole Source Aquifer map

U.S. EPA defines a Sole Source Aquifer (SSA) as an aquifer that supplies at least 50 percent of the drinking water consumed in the area overlying the aquifer. These areas may have no alternative drinking water source(s) that could physically, legally and economically supply all those who depend on the aquifer for drinking water.

The SSA designation protects an area's ground water resource by requiring U.S. EPA to review certain proposed projects within the designated area. All proposed projects receiving federal funds are subject to review to ensure that they do not endanger the water source.

For more information on SSAs, including GIS data, visit http://water.epa.gov/infrastructure/drinkingwater/sourcewater/protection/solesourceaquifer.cfm.

Greater Miami SSA

Allen County SSA

Catawba Island SSA

Pleasant City SSA

Public Drinking Water Supply Beneficial Use

Sampling in a riverIn general, the Division of Drinking and Ground Waters administers Safe Drinking Water Act (SDWA) programs and the Division of Surface Water administers the Clean Water Act (CWA) programs. However, the two divisions share common goals with regard to assessing and protecting sources of drinking water. They have been collaborating since 2002 to strengthen the connection between the CWA and SDWA with more robust assessments of Ohio source waters.

Beneficial Use and the Clean Water Act

DamUnder the Clean Water Act, all of Ohio’s surface waters are designated with specific beneficial uses. How is the water used? Do people swim or boat in it (recreational use)? Do they drink it (public drinking water supply use)? Do they eat the fish they catch (fish consumption)? Do you expect to see aquatic life such as certain bugs and fish (aquatic life use)? Ohio applies the public drinking water supply (PDWS) beneficial use to all waters within 500 yards of an active public drinking water supply intake and all publicly owned lakes.

For each type of beneficial use, there is standard for how clean the water needs to be in order to support each beneficial use (water quality standards and criteria). These standards are used as a "measuring stick" to indicate if waters are meeting or not meeting expectations. Ohio EPA has developed a set of water quality criteria for protection of the public drinking water supply beneficial use and applies the criteria to water quality data collected in the raw source water.

If the waters do not meet expectations, it is considered impaired for that beneficial use. The Ohio EPA must then take action to meet water quality standards. This action typically involves development of a Total Maximum Daily Load (TMDL).

Publications and Fact Sheets

(The Integrated Water Quality Monitoring and Assessment Report indicates the general conditions of Ohio's waters and identifies waters that are not meeting water quality goals. The links below point to the specific chapter in these biennial reports that discusses Public Drinking Water Supply Beneficial Use. To view the entire report, click here.)


Publications and Resources

Guidance Documents, Fact Sheets, Educational Materials and Publications

(If you can't find what you are looking for here, search our Online Publications Catalog.)

Source Water Protection Implementation by Public Water Systems

In mid-January 2015, Ohio’s Source Water Protection (SWAP) program sent letters to 736 public water systems, requesting they fill out an online report identifying the source water protection strategies being implemented in their communities (for municipal systems) or on their properties (for non-municipal systems). Only community public water systems with high or moderately susceptible source waters were targeted. The results are summarized in the following fact sheet.

Annual Drinking Water Source Protection Updates (SWAP Newsletter)

Guidance Documents - Source Water Protection Program

Guidance Documents - Protection Planning

Technical Reports

Fact Sheets - General

Fact Sheets - Technical

Educational Materials