Design Elements — Sewage Facilities
While conservation subdivisions are often encouraged in rural areas to preserve open space and protect natural resources, these areas typically lack access to public sewer infrastructure. In these instances, on-lot or community systems will be needed to accommodate the development which can pose some challenges. The smaller lot sizes typical of conservation subdivisions can make it more difficult to site individual systems on the same lot as the residence it serves. Flexibility in allowing sewage facilities within the protected open space is recommended to address this issue. For example, individual on-lot systems with access easements for maintenance could be located within the open space near the lots they serve. Another option is to allow community systems sized to serve the proposed development. These systems could be conventional land application or drip or spray irrigation systems depending on the specific conditions of the site. In the case of a community system, an HOA will be needed to maintain the system unless the municipality is willing to oversee the system maintenance.
Ordinance Considerations
While municipalities may wish to limit the total percentage of open space that can be used for sewage systems (e.g., 30% to 50%), prohibiting sewage facilities in the open space altogether can have unintended consequences. Not providing for this flexibility may preclude a conservation subdivision on an otherwise ideal site or steer developers towards a conventional large lot subdivision design that can accommodate individual on-lot systems. Note that open space areas with installed sewage facilities are not necessarily precluded from being used for other low impact uses such as passive recreation. Drip irrigation systems can even be installed in existing wooded areas. Additionally, permitting individual off-lot facilities in the open space (versus individual on-lot systems) allows for their placement in areas with the most suitable soils and helps ensure the long-term viability of subsurface sewage disposal systems and avoids future malfunctioning systems.
Sample Ordinance Language
The design of sewage facilities is regulated by the PA Department of Environmental Protection (DEP). However, where these facilities may be sited within a development will be found in a municipality's zoning ordinance that governs conservation subdivisions. Refer to the suggested ordinance language in the Maintain Existing Character and Context design element.