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Adding a Shop to a Home Gravity Septic System




Many rural homesites include a shop, studio, or accessory building in the site layout. It is convenient to include at least a toilet and sink in the plans for the separate shop, studio, or home office if any amount of time is to be spent there. Most health jurisdictions do not require any expansion of the septic tanks or drainfield to accommodate a shop or studio because without adding a bedroom, the population of the site, and therefore the sewage design load does not change.

The issues instead are cross-connection conflicts between several water and sewer lines crisscrossing around buildings and moving sewage in shallow sewer lines without getting lines too deep in the ground to meet regulations. We include construction plans covering 5 main situations involving the house/shop combination.

Don’t move ahead connecting sewer and water to a new shop or studio or any other accessory structure on your homesite without first checking with local health. If septic systems are regulated in your area, additions and alterations to septic systems are too, and require permits. Health inspectors are always concerned with potential cross-connection issues between sewer and water systems. The last thing you need during a final building inspection of the house is a surprise notice to schedule a health inspection you thought not necessary. Standing in your unfinished living room nose-to-nose with a county official is not how you want to explain your sanitary design. They can make you dig it up and change your layout, or make you add a sleeve to the water line or any number of frustrating, time-consuming, and expensive fixes.

Our Drawing Templates are in standard PDF and CADD (DXF) formats.

Every county, parish, or territory can have unique individual rules about the design, construction, maintenance, and permitting of septic systems and water systems. However, all local health guidelines must also meet state or provincial regulations which tend to conform to universal standards of public health. Eco-nomic’s drawings and design templates have been sold in hundreds of counties and territories since the 1990s and these drawings represent the first universal standard in septic design for most on-site wastewater situations.

The drawings are in both PDF and easily edited CADD formats. You can use our designs to discuss your project with clients, contractors, or regulators while you are in the planning phase. Later, the drawings can be personalized and submitted for a health permit to represent your property and what you want to build. We do not claim that our standard designs can be approved in every local health office. But we DO guarantee that you can customize our drawings with any standard CAD program like AutoCAD, SolidWorks, or SketchUp to submit professional plans to the permitting agency to build your project.

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