15A-NCAC-2C-.0107-Clarification-FINAL-ds

February 19, 2021

MEMORANDUM

TO: DEQ Division of Water Resources Staff
DHHS On-Site Water Protection Branch
All Interested Parties

FROM: Danny Smith, Director
NCDEQ Division of Water Resources

SUBJECT Clarification to 15A NCAC 02C .0107(a)(2)(A) and (B)

The North Carolina Division of Water Resources (DWR) and Department of Health and Human
Services (DHHS) have received inquiries relating to the recent readoption of 15A NCAC 02C
.0107(a)(2)(A) and (B) (Standards of Construction: Water Supply Wells). This rule, which became
effective June 15, 2020, references the horizontal separation distances of private water supply
wells in relation to subsurface sewage treatment and disposal septic systems. An excerpt of the
rule is as follows:

15A NCAC 02C .0107 STANDARDS OF CONSTRUCTION: WATER SUPPLY WELLS
(a) Location.
(2) The horizontal separation between a water supply well and potential sources of
groundwater contamination that exist at the time the well is constructed shall be no
less than as follows unless otherwise specified in Subparagraph (a)(3) of this Rule:
(A) Single-family dwelling with septic tank and drainfield, including the
drainfield repair area - 50 feet.
(B) Single-family dwelling with septic tank and drainfield, including the
drainfield repair area in saprolite system as described in 15A NCAC 18A
.1956 - 100 feet.

The inquiries DWR have received has been in regards to the horizontal separation distances
(setbacks) stated in the rule. As written, it is not clear if the setback requirements refer to the
distance of a well to a residence, or the distance of a well to a septic tank system. Since these rules
became effective in 1976 and amended over the years, the setback distances have been the
distances between a well and a septic system, not from a well to the residence/structure.

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Prior to the readoption of 2C .0107(a)(2)(A) and (B), the rule previously stated in referencing
separation distances for a well- “Septic tank and drainfield, including drainfield repair area.” The
readopted revision now states- “Single-family dwelling with septic tank and drainfield, including
the drainfield repair area.” This new phrasing may cause confusion because it could be interpreted
to specify the setback for a well to a single-family dwelling, and not to the septic system itself.

Session Law (SL) 2018-65 (Section 4.(c)(1)) amended language in 15A NCAC 02C
.0107(a)(2)(A) to declare that the minimum horizontal separation distance between a well serving
a single-family dwelling and a septic tank and drainfield (including the drainfield repair area), shall
be 50 feet (unless it is a septic system installed in saprolite). This change reduced the requirement
for water supply wells to be located from a septic system/drainfield or repair area from 100 feet to
50 feet (if serving a single-family dwelling). The SL only reduced the setback distance between a
well and septic tank. It did not modify the rule to state the setback should now be between a well
and a residence/structure.

Therefore, in order to aid regulatory agencies and the general public, this memo is intended to
clarify the setback requirement language found within current 15A NCAC 02C .0107(a)(2)(A) and
(B). The minimum horizontal separation between a water supply well, serving a single-family
dwelling, and a septic tank and drainfield, including the drainfield repair area, shall be 50 feet.
The minimum horizontal separation between a water supply well, serving a single-family dwelling,
and a septic tank and drainfield, including the drainfield repair area for a saprolite system as
described in 15A NCAC 18A .1956, shall be 100 feet.