NOT IN MY BACKYARD, ANYMORE: A SUCCESSFUL BACKYARD SEWER REPLACEMENT PROGRAM

PurposeTo present the process of designing and constructing a successful backyard sewer replacement project in a well-established, older neighborhood. To discuss the obstacles, challenges, and public concerns that needed to be addressed to obtain homeowner buy-in of the project and to provide a safe construction environment.BenefitsThe paper will share lessons learned in the design and construction phases of the project and provide suggestions to others on how to gain project acceptance from multiple stakeholders.Status of CompletionThe construction project is in progress and will be substantially complete by the date of the conference.NarrativeBackyard sewers are common in many older sewers in American cities. The sewers in many residential subdivisions built in the 1950s were installed in the backyards of residences, along property lines or easements, because it was easier to put them there than in the street. Thus avoiding construction traffic disruption as new houses were built. In many older neighborhoods that originally had septic tanks and drain fields, it was easier to connect the lateral in the back of the house to a backyard sewer. This all seemed like a good approach back in the day. But, as any Collections System Operations and Maintenance supervisor will tell you, back yard sewers are difficult to maintain.Eliminating back yard sewers often involves constructing a new main line sewer in the street in front of the house and routing the sewer lateral around the house, from the back to the front. To do this, the designer must resolve many issues. Over the years home owners make improvements to their properties such as constructing fences, sheds, and other structures in the their back yards and by planting trees and shrubs along the property line. These amenities inhibit maintenance crew access and make manholes and cleanouts hard to find. Older sewers that were poorly constructed and have open, leaky joints contribute to higher wet weather flows due to infiltration and inflow (I/I). Open joints can also contribute to root intrusion and cave-ins due to soil migration, both of which can cause sewer blockages. Poor access makes clearing blockages with conventional truck mounted equipment difficult if not impossible. Sewer access problems, homeowner complaints, and the need for I/I reduction drove the City’s decision to eliminate the back yard sewers in the project area.Homeowners also make improvements to their property that inhibit routing new laterals around the house, such as garden and flowerbed hardscapes, ornamental structures, privacy fences, decks, driveway and sidewalk extensions, and trees and shrubs. In the project area, all of these things had occurred over the years, and the property owners took pride in how their yards looked. The neighborhood had been constructed in the mid 1950’s in a previously wooded area that contained many large white oak trees, some with diameters of 4 or more feet, hence the name of the neighborhood, White Oak. Because of the age of the neighborhood many trees that were planted years ago were also big and well dispersed about the properties.Another consideration in design of the new house laterals is the minimum slope required by the local building code, usually about 1%. This can become an issue at the end of the main line sewer where it is shallower and long lateral runs may be necessary. Maintaining vehicular and pedestrian access to properties during construction is an absolute requirement. Traffic control plans can become extensive and require several phases to construct the project.Our approach to addressing the project constraints and considerations discussed above included:Inspecting and photographing properties to document the existence of features that could impact lateral re-routing.Having discussions with property owners during the field inspections to hear their concerns.Sending maps of the proposed lateral re-routing to each property owner with a form requesting their acceptance and any information on abandoned septic tanks or underground fuel oil tanks.Conducting a public meeting at a nearby venue to describe the project and to get feedback from property owners.The project is currently under construction, with few complaints, and will be completed in the next several months.