Pursuant To: 15A NCAC 18A .1950(b) and 15A NCAC 2C .0100
Source: Nancy Deal, Onsite Water Protection Branch Head
The Onsite Water Protection Branch has received inquiries relating to a letter from then Section Chief Bill Jeter dated Feb. 13, 1997. The purpose of this Position Statement is to provide clarification and update guidance on subsurface sewage treatment and disposal system locations in relation to private water supply wells in accordance with 15A NCAC 18A .1900, Sewage Treatment and Disposal Systems and 15A NCAC 2C .0100, Well Construction Rules.
Background
15A NCAC 18A .1950(b) states that “Ground absorption sewage treatment and disposal systems may be located closer than 100 feet from a private water supply, except springs and uncased wells located downslope and used as a source of drinking water, for repairs, space limitations, and other site-planning considerations but shall be located the maximum feasible distance and in no case, less than 50 feet. Casing is defined in 15A NCAC 2C .0102(7) as pipe or tubing that is installed in a borehole, during or after completion of the borehole, to support the side of the hole and thereby prevent caving, to allow completion of a well, to prevent formation material from entering the well, to prevent the loss of drilling fluids into permeable formations, and to prevent entry of contamination. The materials used when completing a bored well may differ than that of a drilled well, however, the casing in both cases is intended to meet the requirements as defined in 2C. 0102.” (Emphasis added.)
Furthermore, 15A NCAC 2C .0113(c)(3) states when abandoning a bored well “the uppermost three feet of well casing shall be removed from the well.” The fact that the rules identify those materials associated with bored wells as casing further reinforces the argument that bored wells are in fact “cased” wells.
Conclusion
A properly constructed and grouted bored well can be located within 100 feet, but in no case less than 50 feet to a sanitary sewage treatment and disposal system. Note that the maximum feasible separation distance shall be used in siting the well. The Local Health Department should ensure that the well appears to be properly grouted prior to permitting a system less than 100’ from the bored well. Should there be questions concerning the integrity of the well, it is further recommended that the well be inspected by use of a downhole camera to ensure that shallow water is not leaching into the well at depths less than 20’ below land surface.
Please direct any questions you may have to your Environmental Health Regional Specialist or Regional Soil Scientist.