1995-08-17 Work Session
NEW HANOVER COUNTY BOARD OF COMMISSIONERS
WORK SESSION, AUGUST 17, 1995
BOOK 24
PAGE 866
ASSEMBLY
The New Hanover County Board of Commissioners held a Work
Session on Thursday, August 17, 1995, at 10:25 A.M. in Room 501 of
the New Hanover County Administration Building, 320 Chestnut
Street, Wilmington, North Carolina.
Members present were: Commissioners Sandra Barone; WilliamA.
Caster; William E. Sisson, Jr.; vice-Chairman E. L. Mathews, Jr.;
County Manager, Allen O'Neal; Assistant County Manager, Dave
Weaver; and Clerk to the Board, Lucie F. Harrell.
Chairman Greer was absent.
vice-Chairman Mathews called the meeting to order and
announced the purpose of the Work Session was to hear a
presentation from the N. C. Division of Environmental Management on
the North Carolina Wellhead Protection Program. He welcomed the
following officials from the N. C. Division of Environmental
Management Groundwater Section: Mr. Carl Bailey, Assistant Chief
of the Planning Groundwater Section and Mr. Randy Prillaman.
Mr. Bailey and Mr.
presentation:
Prillaman presented the following
PRESENTATION OF NORTH CAROLINA WELLHEAD PROTECTION PROGRAM
In 1985 Congress amended the Safe Drinking Water Act to
require the development of state wellhead protection programs.
These programs are a key part of the national groundwater
protection strategy to prevent contamination of groundwaters that
are used as public drinking water supplies. The North Carolina
Wellhead Protection Program is part of this national strategy.
In North Carolina, wellhead protection complements the State's
on-going program to reduce the potential for groundwater pollution.
Although it is the State's responsibility to develop standards for
wellhead protection programs, local governments control the legal
mechanisms, such as land use and subdivision regulations, to
implement specific wellhead protection objectives.
Reducing threats to groundwater water supply through wellhead
protection consists of two basic components:
I. Delineation of Wellhead Protection Areas: There is not a
single method of delineating a wellhead protection area.
various delineation methods have been developed for use in a
variety of situations and circumstances. The following
methods are used most frequently:
(a) Calculated Fixed Radius Method: The calculated fixed
radius method results in a circular wellhead protection
area with a radius dependent upon certain hydrogeologic
and well factors. Analytical equations are applied to
determine the contributing area to be protected. A
circle with the appropriate area is then drawn around the
well. This method is easy to apply with a limited amount
of technical expertise. It offers the potential for
increased accuracy over the fixed radius method.
However, it may also be inaccurate, particularly in areas
of variable hydrogeologic conditions or where flow
boundaries are present.
(b) Simplified Variable Shape Method: The simplified
variable shape method consists of defining an appropriate
variable shape wellhead protection area based on
hydrogeologic and pumping conditions. The size and
orientation of the variable shape wellhead protection
area is determined using analytical equations and flow
pattern data. This method requires a little more
information and expertise than the calculated fixed
NEW HANOVER COUNTY BOARD OF COMMISSIONERS
WORK SESSION, AUGUST 17, 1995
BOOK 24
PAGE 867
radius method, but can potentially improve accuracy. Care
must be taken in determining groundwater flow direction,
especially where hydrogeologic conditions are highly variable.
II: Inventory of Potential Contamination Sources: Once the
wellhead protection areas have been delineated, the next step
is to identify and locate potential contaminants. The purpose
of the inventory is to understand the nature and magnitude of
potential threats to water quality and human health contained
within wellhead protection areas.
III: Management: Management strategies can be developed to prevent
contamination of water supplies. The inventory can focus on
specific substances that would become a threat to underground
water supplies or land-use activities that typically involve
the production, use, transport, or storage of those
substances. In managing wellhead protection areas, it is more
useful to identify and regulate a relatively small number of
land use activities that are a threat to groundwater quality
in lieu of identifying and regulating many hundreds of
individual substances. The most common land-use activities
that are potentially sources of groundwater contaminations are
laundries, auto repair shops, textile and apparel products,
and chemical and petroleum storage and sales.
In summary, a local wellhead protection program provides local
governments with administrative authority and flexibility to
protect public underground water supplies. A local program can be
structured to complement the State's program in two areas, such as
construction inspection, and periodic inspection. However, the
State will not relinquish its responsibilities for plan and
specification review of public community well systems, and
enforcement of State rules and regulations.
Discussion was held on the need to protect the quality of
groundwater in New Hanover County. Mr. Hank Lyon, Chairman of the
Groundwater Task Force, recommended proceeding with implementing a
Wellhead Protection Program in New Hanover County, which would
begin by holding a one day Workshop that would be sponsored by the
Groundwater Section of the Division of Environmental Management.
Mr. Bailey reported the Groundwater Section would be glad to
schedule a one day Workshop. The County would be responsible for
furnishing a meeting room and a list of persons attending the
meeting. The departments involved with water quality and the
elected officials would be invited as well as the general public.
vice-Chairman Mathews, on behalf of the
appreciation to Mr. Bailey and Mr. Prillaman
presentation.
Board, expressed
for an excellent
ADJOURNMENT
Vice-Chairman Mathews adjourned the meeting at 11:20 A.M.
Respectfully submitted,
Lucie F. Harrell
Clerk to the Board