(A) Extent of Wellhead Protection Area. The Wellhead Protection Area (WPA) consists of two areas (WHPA Zone 1 and Zone 2) which are listed and described below.
(1) WPA Zone 1. WPA Zone 1 area extends approximately 100 feet radially from the wellhead, representing an eight week capture zone that is determined on the basis of groundwater flow direction and recharge.
(2) WPA Zone 2. WPA Zone 2 Area extends from the wellhead, including WPA Zone 1, to include the 40 year capture zone that is determined on the basis of groundwater flow direction and recharge.
(B) Wellhead Protection Area delineation. Boundaries for the Wellhead Protection Area zones for the Wellhead Protection Overlay Districts are shown on published maps entitled “Town of Collierville Wellhead Protection Overlay Map” and are adopted by reference as part of this subchapter as if the maps were fully described herein. The boundaries of the Wellhead Protection Areas, Zone 1 and 2, were based on the predicted groundwater flow pattern in the vicinity of the Town of Collierville Wellfields.
(C) Delineation methodology.
(1) Wellhead Protection Areas, Zone 1 and Zone 2, were delineated using the numerical method to predict the groundwater flow patterns surrounding the wellhead, using a county wide regional flow model as defined in Zone 1 and Zone 2 reports approved by TDEC (November 1995). The eight week capture zone (Zone 1) and the 40 year capture zone were delineated through the simulation of groundwater flow or movement as a function of pumping rates, acquifer characteristics and static water table/piezometric surface conditions.
(2) The aquifer characteristics were determined from geophysical well logs generated for the Town of Collierville, at the time the wells were drilled, combined with data from adjacent municipalities.
(D) Amendment of Wellhead Protection Area.
(1) The Wellhead Protection Areas may be reviewed and modified annually by the Board of Mayor and Aldermen, at the beginning of each calendar year, and the Wellhead Protection Overlay Map may be revised accordingly.
(2) Every three years, substantial changes may be made to the Wellhead Protection Overlay Map by the Board of Mayor and Aldermen, in order to show the location of new wells, update the Town’s Contaminant Source Inventory, adopt better modeling techniques and incorporate recent and more accurate hydrogeologic data.
(E) Location of properties. In determining the location of properties within the Wellhead Protection Areas, Zone 1 and Zone 2, depicted on the Wellhead Protection Overlay Map, the following rules shall apply.
(1) Properties located wholly within one zone reflected on the Wellhead Protection Area Overlay Map shall be governed by the restrictions applicable to that particular zone.
(2) Properties having parts lying within more than one zone as reflected on the Wellhead Protection Area Overlay Map shall be governed by the restrictions applicable to the zone in which that part of the property is located.
(3) Where a time-travel contour which delineates the boundary between two zones of influence passes through a building, the entire building shall be considered to be in that zone with the greatest restrictions as of April 1, 1998.
(4) Where any capture zone extends beyond the corporate limits of the Town of Collierville, the portion of the capture zone within the adjacent municipality, per prior agreement between the subject municipality and the Town of Collierville, shall review any proposed or existing land use utilizing this subchapter.
(`00 Code, § 11-1704)