There are 2 major ways to get more bedrooms approved for your septic permit.
1) Increase your LTAR (long-term acceptance rate). This number describes how many gallons per day per sq ft of drain field space can be applied sustainably to the soil without failing.
2) Reduce your horizontal setbacks and open up more area on the property for drainfield area. Treating wastewater before applying it to the drainfield area allows property owners to reduce the horizontal setback distance they must maintain between their drainfield an property features like: foundation drains, surface waters, interceptor drains,
If your property is near a body of water like Lake Norman or on the coast we oftentimes utilize a combination of both 1 and 2 through the use of treatment technology, innovative drainfield products and a thorough understanding of onsite wastewater rules.
For example, on Lake Norman, where soils are normally pretty good, a drainfield product like T&J Panel is used to reduce the required footprint of the drainfield by 50%. Pairing T&J Panels 50% drainfield reduction with the horizontal setback reductions of Ts-i or ts-ii treatment and homeowners are able to gain additional bedrooms, pool area, or other valuable additions to their property.
At the coast, we use ts-ii treatment and bed systems to squeeze drain fields for an 8 bedroom home in to a little over 400 sq ft.
The 1970 Rules are the rule book in North Carolina that the local environmental health department and soils and engineering professionals use as guidelines for septic system design.
Thankfully the 1970 rules are undergoing a rewrite to make them more readable and easily understood. In the meantime, reach out to AQWA for help tackling your onsite wastewater design challenges! firstname.lastname@example.org