Septic Systems & the Landscape by Nancy Fleming From the Weston Land Trust Newsletter, March 1997
Title 5 is a Commonwealth of Massachusetts environmental code aimed at preventing ground water pollution caused by failed septic systems. Title 5 regulations have resulted in a dramatic increase in the number of new septic systems. Since a Title 5 inspection is required for property transfer, realtors are a good source of referrals for a registered professional engineer or a registered sanitarian to design a system and a contractor who has an installer's permit from the Weston Board of Health. An ideal approach to the design process is to include two other professionals in the initial discussion: a registered arborist to evaluate existing trees and a landscape architect or landscape designer to explore ideas for an overall plan for the property.
To construct systems large enough to accommodate new houses and new additions, installers might remove trees, possibly valuable mature trees. There are three possibilities of losing additional trees: 1) If roots of trees adjacent to the leaching field are cut off, a tree may lose up to 50% of its nourishment and also lack stability in major storms. 2) If fill is laid on top of an existing grade of earth next to the new system, tree roots may be starved of oxygen. 3) Heavy equipment at the construction site will compact the earth, depriving tree roots of oxygen.
Another major consideration in the design process is that no trees or shrubs can be planted over a leaching field or within five feet of the outside edge of the field. Grass, ground covers, perennial gardens or a meadow with wildflowers are the only planting options. Graphic renderings or Photoshop computer simulations can help in visualizing properties with trees removed. Using projected after photographs or sketches of the site, owners can better evaluate existing trees, which may provide an important screen from the road or neighbors. They can then explore more creative landscape design possibilities with the engineer who designs their system.
Homeowners would be wise to think about future needs for landscape improvement as part of the overall design process. Once a leaching field is built, no heavy equipment can be driven over it. Since we grow rocks in New England, a by-product of construction may be granite in all sizes. Rocks can be trucked offsite or incorporated into a landscape design. If owners plan to build a retaining wall or place large boulders as focal points in the landscape, they should mention this in initial discussions with the installation contractor, who will have heavy equipment on the site and can move rocks before laying the pipes.
Above-ground septic systems, needed in certain circumstances, provide additional design complications. There are regulations against altering runoff patterns to adjacent properties. For purposes of visualization, a designer can proved a sketch showing how four or five feet of fill over the large area of a new septic system will change the landscape. In summary, with careful planning, residents can design changes to their landscape which have both practical and aesthetically pleasing results.