Zoning ordinances, subdivision regulations, and building codes are traditional and
used land use measures that can be designed to protect surface and ground water

Alternative zoning tools also have been designed to provide flexibility to develop in more
environmentally sensitive ways according to the opportunities and constraints of specific land parcels. Often, using these alternative tools is the most effective way to protect drinking water supplies.

While some of the source water protection tools … are not regulatory, effective implementation of land use authority to protect water supplies requires that local officials examine their land use programs to determine whether changes should be made. In addition, some land use control measures are more effective in preventing potential water supply threats from being sited in the source water protection area than they are in addressing land use activities that are already in place.

Excerpt from Source Water Protection: A Guidebook for Local Governments


Zoning is the division of land in a municipality or county into districts and applying land use regulations uniformly through each district. Within each district, the zoning ordinance can specify permitted uses, lot size, and design and performance requirements for specific
activities. Zoning is widely used by towns to guide development under a comprehensive plan and can be adapted to protect land around surface water intakes or wellheads.

Generally, regulatory tools require sufficient administrative and technical resources to carry them out and ensure compliance. Regulations must be specific and must address actual threats or problems appropriately to avoid court challenge. Because regulatory tools
require legal authority, issues of jurisdiction must be dealt with at the start. A town with a source water protection area (SWPA) contained entirely within its borders can control planning, management and future development through town policies and ordinances. A town with all or part of its protection area outside its  borders cannot zone beyond its
jurisdiction.  To be effective, the town must cooperate with the neighboring town(s) or approach the county to include it in the countywide zoning program.

The Pennsylvania Municipalities Planning Code (MPC), establishes a legal framework for local planning and zoning in the state.  The MPC also permits joint municipal planning and zoning.  This allows for a shift of the responsibility for providing for the full range of potential land uses among municipalities.  Joint municipal zoning can be a very useful tool for protection of water supply areas and source water protection.  Communities that share and are motivated to protect a common ground water or surface water resource have the ability to jointly determine key source water protection land areas.

Zoning for Source Controls

Because zoning is meant to promote public health and safety, limiting or banning the use of specific hazardous substances for the purpose of protecting water supplies is a permissible zoning measure. Zoning districts especially overlay districts, can be defined to prohibit the use of substances that would be hazardous to the drinking water supply or activities that use such substances.

Zoning for Performance and Design Standards

Through zoning, local governments can guide structure design and set standards to ensure that certain activities do not threaten the drinking water supply. Design standards can require certain safety precautions for activities that might threaten drinking water, such as facilities that store or handle pesticides or solvents. Performance zoning sets standards for permissible effects of land use activities; any use is allowed in the zone as long as standards are met. This technique is commonly used to set standards for noise and dust in industrial areas; for SWPAs, performance standards can limit the amount of hazardous substances stored on site or promote control of runoff from storage and loading areas.

Zoning for Density Standards

Reducing the number of housing units can reduce the impact of residential development within the SWPA. Requiring large lots in unsewered developments, for example, reduces the number of units within the SWPA, reducing the amount of septic system leachate. Cluster zoning increases density in a section of a zone while the remaining area of the zone is left in open space. Average density throughout the zone remains the same. Cluster zoning can be used to guide more dense residential development to outside the SWPA, while not restricting the total number of units allowed.

Statutory Authority

Section 1428 of the Federal Safe Drinking Water Act Amendments of 1986 requires States to establish Wellhead Protection Programs to protect groundwater from contamination.

In Pennsylvania, the responsibilities for development and implementation of Wellhead Protection Programs, which has now been broadened to include Source Water Protection Programs,  is shared between water suppliers, the Commonwealth and local municipal governments. The Pennsylvania Department of Environmental Protection (DEP) recognizes that, in Pennsylvania, DEP is responsible for regulating water suppliers and discharges of contaminants. DEP also recognizes that it is the responsibility of local governments to regulate land use. Local governments are empowered, under the provisions of the Pennsylvania Municipalities Planning Code (MPC), as amended, 53 P.S. § 10101, to enact ordinances regulating development and land uses.

There are a variety of Regulatory Tools that can be deployed as part of a Source Water Protection Plan, including:


PA Drinking Water Regulations

Pennsylvania Department of Environmental Protection (PADEP) Drinking Water Regulations, Standards, Source Protection, and Resources Website -Go >>

PADEP Drinking Water Regulations – Go>>

Fact Sheets

World Health Organization: Optimizing regulatory frameworks for safe and clean drinking-water – Protecting drinking-water sources through regulation


For Model Ordinances, model documents, a variety of Guides specific to Pennsylvania, and an entire section on Riparian Buffers with ordinance examples,  go to the Pennsylvania Land Trust Association’s helpful website at www.conservation tools.org

Pennsylvania Municipalities Planning Code (19th edition)

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