Strategies for Rural Development in Areas with Limited Public Infrastructure: Alternative Septic Systems

Case Study 2: New Decentralized Sanitary District

Summary

A rural town in Maine with no public sewer or water lines identified the area around an existing village, anchored by a community school complex and a thriving residential neighborhood, as its growth area. The area fronting the main road west of the village was designated for “planned development” (i.e., mixed-use), but the town’s land use ordinance continues to reflect outdated concerns about onsite wastewater disposal requirements by mandating large minimum lot sizes.  The archaic land use standards reduce the likelihood that commercial and residential developers will be attracted to its designated growth area.

A 139-acre lot in this town’s “planned development” zone could theoretically support both commercial and residential development.  If the land use ordinance were updated to permit minimum allowable lot sizes (per Maine’s wastewater disposal laws), individual drilled wells, and community septic systems for wastewater disposal, the subdivision of this lot could safely accommodate:

To encourage and accelerate this level of dense mixed development, the town might first opt to create a new sanitary district to own and operate the two community septic systems. Working with landowners in the growth area, the district could acquire land for the community septic systems to facilitate future development.  The district would finance the construction of the common leach fields (the wastewater treatment system).  Developers would be responsible for the cost of installing septic tanks on individual lots and connecting them to the appropriate community leach field, and also would pay a pro-rated assessment for each lot to repay the sanitary district’s up-front costs in constructing the community leach fields.  After the project was completed and inspected, the sanitary district would assume ownership and maintenance for all of the collection systems as well as the leach fields, with a deeded right of entry to inspect and maintain individual septic tanks on a periodic basis. Property owners connected to the system would pay monthly fees to the district to cover the costs of operating and maintaining the system, just as they would if they were on a public sewer line.

The Town of Warren, Vermont, developed two large community septic systems as components of a larger decentralized wastewater project that also included onsite septic systems where appropriate, to ensure good opportunities for future development within its compact, pre-industrial village area.  For more information on the project in Warren, VT, click here.

Case Study Two: Details

The Setting:  In Case Two, the community is a demographically small, but geographically large town in Maine.  There are still extensive rural lands throughout the town, but it is rapidly transitioning from a small-town community into a bedroom suburb for a nearby large city.  The comprehensive plan designates three growth areas in different parts of the town, each around or near a long-time settlement.  The largest of the growth areas encompasses an existing village, a community school complex, and a westerly extension of the village along an arterial highway that already contains some homes and small businesses. 

The part of the growth area extending from the village area west along the arterial has been designated in the comprehensive plan as a “planned development.” It was found to have acceptable soils for subsurface wastewater disposal systems, no major environmental limiting factors, good road access, and several successful commercial activities that are likely to attract more residents and businesses into the corridor.  The comprehensive plan specifies that the planned development district “allow a mix of both residential and commercial uses” and expresses a desire for new development in the growth area to maintain the small-town atmosphere of the existing village.

Although the plan prescribes a mixed-use area “designed to shift development pressure from rural portions of the town” and “able to accommodate the growth anticipated by this Comprehensive Plan,” the proposed minimum lot sizes are one acre per residential unit, and two acres for each commercial use.  These large lot standards reflect unwarranted assumptions about development with subsurface waste disposal, and they are clearly not conducive to developing a densely settled village in the growth area. aerial photo

The Conditions:  The growth area contains a total of just less than 975 acres, including the existing village and the “planned development” area to the west.  Over 700 acres of this total are contained on approximately two dozen parcels within the growth area, with lot sizes ranging from 10 to 100+ acres.  Many of these lots are developed with one single-family home, but most of the land is vacant.  A fair amount of lot-by-lot subdivision and development has already occurred along the frontage of the main road, but large tracts of vacant land lie behind this development on either side of the road.  The land includes a mix of active and abandoned farm fields and woodlands.

The area is not served by public water or sewer, and no utility districts serve the town.  Soils are mostly fine and very stony fine sandy loams, moderately to excessively well drained.  Large portions of the area have bedrock 18 inches below the surface, but in other portions, bedrock is more than five feet deep.  Some wet soils and small wetlands exist along drainage ways.  Topography is not a limiting factor.  Two small public wells are located within the growth area.

Estimated Building Potential:  This case study focuses on two contiguous, primarily vacant parcels totaling 139 acres, located within the designated “planned development” portion of the growth area.  The parcels are within walking distance of existing schools, shops, and services. They also have good access to the area’s robust transportation system, including a limited-access highway.

About half the site is fine sandy loam, well drained but shallow to bedrock (10 to 20 inches). About a quarter of the site is fine sandy loam or very stony fine sandy loam, both deep and moderately well drained.  About a fifth of the site is a different type of very stony fine sandy loam, a portion of which is associated with a drainage way and surface wetness, including about 18 acres that are unbuildable.  Smaller inclusions are of the MARLOW series, which are fine sandy loams, deep and well drained.

Two of the MARLOW inclusions are conveniently located for easy access and maintenance, and both are over 300 feet from existing private wells and a quarter mile from the closest public well. This makes them ideal for placing community wastewater disposal fields.  Wastewater systems in these soils must be designed using the “medium-large” standard.

The buildable area within the two sites is an estimated 121 acres.  In the spirit of the planned development district, a portion of the land could be earmarked for small-scale commercial activity.  A community wastewater disposal system located on a MARLOW soil with a design flow of 20,000 gallons per day would require, including provision for setbacks, just less than 5 acres of land.  This design flow could accommodate a mix of commercial activity (e.g., a small restaurant and lodging facility, offices with up to 100 employees, a 10-machine laundry, and small stores with up to 100 employees).  This mix of activity, if developed using the design standards proposed in the town’s comprehensive plan, would require approximately 20 acres, including off-street parking for each commercial lot. If designed compactly and with on-street parking, in more of a traditional downtown village style, it would require even less land. aerial photo with plan

This would still leave about 100 acres for residential purposes, including open space.  Again, in keeping with the concept of the “planned development,” a mix of small-scale multifamily development and single family homes could be placed close to the community school complex.  In theory, the Minimum Lot Size Law would allow more than 200 dwelling units on the 100 acres.  However, following the local zoning protocol of subtracting out acreage dedicated to the community waste disposal system, streets, etc., that number is reduced to 150 units. 

The size of the community wastewater system needed to accommodate this number of units depends on the mix of residential units.  The area available for the subsurface wastewater disposal system for this portion of the development is about four acres, and could accommodate a flow of 31,500 gpd.  This would support 150 units, if 100 were 2-bedroom apartments and 50 were 3-bedroom single family homes.  Alternatively, it could support 50 2-bedroom apartments and 80 single-family homes, or 25 2-bedroom apartments and 100 single-family homes.

In summary, the potential development program for this case study might be:

Of course, there would need to be a minimum of 300 feet between the community leach fields and individual drilled wells, which might increase the area earmarked for the leach fields plus setbacks. The multifamily units would probably be served by a single community well for the entire complex.  If so, the wellhead protection area would likely require an area larger than the minimum 300-foot radius, particularly in the upgradient direction.  The services of a Professional Engineer or Hydrogeologist would be crucial to determine the appropriate separation distances between any proposed community wells and the components of the community septic systems.

In any case, these estimates suggest that the use of community wastewater disposal systems would enable just two lots within the designated growth area to safely absorb 30 to 40 percent of all the housing growth forecasted to occur in this town over the next decade.  The overall density of the residential portion of the development would be 1.2 to 1.3 units per gross acre.

Managing the System:  Maine state law provides this town with the means to implement its “planned development” vision for this growth area.  Communities are allowed to establish sanitary districts to cover a whole town, a section of a town, or a several towns within a region.  (However, the current law does have a few limitations.  These limitations, along with proposed amendments that would encourage more widespread use of decentralized wastewater disposal options in Maine, are discussed in greater detail at the end of this section.)

The town could establish and enable a new sanitary district that would own and operate small-scale community subsurface wastewater disposal systems serving the designated growth area, which would also be its defined jurisdiction.  Working with owners of developable tracts of land in the growth area, the district could acquire land from willing sellers for community wastewater systems in advance of development.  The district would finance the construction of the community leach fields, likely through a combination of "readiness to serve” charges to the benefiting property owners and low-interest loans from the State Sewer Revolving Loan Fund.  As land in the growth area is developed, developers would be responsible for installing individual collection systems (onsite septic tanks with lines and pumps as needed to direct effluent into the appropriate leach field) at their cost, following the specifications of the district and the state’s wastewater disposal rules.  Once completed and inspected, the collection systems would be turned over to the district, along with legal easements giving the district the right and responsibility to maintain the collection systems (including periodic pumping of septic tanks) as well as the leach fields.  Property owners connected to the community system would be charged user fees to pay for its operations and maintenance, including repayment to the town of any incurred loans, similar to the way property owners on public sewer lines are charged fees for their operation and maintenance.

If a proposed development were large enough, the sanitary district should have the option to authorize the developer to construct the community wastewater field(s), then turn them over to the district upon completion.  This approach would be more appropriate if (1) the district has not yet built a facility that is accessible from a particular developer’s parcel, and (2) the developer believes that the size of the development and its sales revenues would allow full recovery of the capital costs for the community wastewater system within a reasonable period of time

Implementing the plan: This town’s land use regulations will need be changed to encourage compact mixed-use development as envisioned in the comprehensive plan.  The following basic principles will need to be enacted:

Amending Maine law to meet the needs of decentralized wastewater management systems: The current language in Maine’s Sanitary District Act is quite flexible and meets the needs of communities in most situations.  However, because the bulk of it was written 20 to 30 years ago, little specific provision was made for (1) subsurface wastewater disposal (the law assumes that  sanitary district discharges will enter surface waters), or (2) small decentralized community systems  (the law assumes that all “public sewer systems” are large-scale and centralized).

Several procedural requirements, as well as some of the powers and authorities granted to large-scale municipal or regional sanitary districts, may not be needed or appropriate for small decentralized community systems that essentially serve a single neighborhood.  For example, a sanitary district can only be established within a community upon the filing of an application with the Board of Environmental Protection (BEP) by the municipal officers, a positive finding by the BEP, and a referendum vote by “the legal voters residing within the portion of the municipality, municipalities or unorganized territory that falls within the proposed sanitary district.”  In the case of decentralized community systems serving a relatively small number of properties, decisions by the municipal officers in consultation with the affected land owners and BEP staff may be sufficient.  Certain existing powers of a typical sanitary district, in particular the power of eminent domain, may be distasteful to town residents who are being asked to approve the establishment of a district to manage decentralized community systems, thus hindering efforts to secure the needed votes to establish a district. Small community septic systems are almost always created either on town-owned parcels or on land purchased under “willing buyer, willing seller” arrangements, so the eminent domain power just raises an unnecessary red flag for the town’s citizenry, fueling fears that private property will be seized by the new district to create sprawling leach fields throughout the community.

The Sanitary District Act should be amended by recognizing the somewhat hybrid nature of a Decentralized Community Sanitary District.  It will typically have the size and jurisdiction of a large homeowners’ association, yet it must wield sufficient autonomous decision-making power  to fulfill the requirements of an “independent entity” as defined in Maine’s Subsurface Wastewater Disposal Rules.  The focus of amendments to the existing law should be on enabling small-scale districts to manage and maintain community wastewater disposal systems, specifically to aid in the implementation of designated growth areas as identified in approved comprehensive plans.

Suggested language for amending the existing Sanitary District Act is provided here.  Interested municipal officials and developers are encouraged to contact their local state legislators to encourage sponsorship and passage of an amendment during the next legislative session.

 

Related Work Plan Components

Workgroup Contacts

In Aroostook County: Jay Kamm, Ken Murchison, Joella Theriault

In Washington County: Judy East