§ 28-265. Groundwater resource, wellhead and special protection areas.

(a)

Establishment. The entire land area within Hernando County is designated as a groundwater resource protection area. The county shall designate wellhead protection areas (WHPAs) for all community public water supplies. Community public water supplies shall be classified based on the average permitted capacity of the supply. Two (2) WHPAs will be calculated for community water supplies permitted on average to pump greater than or equal to one hundred thousand (100,000) gpd. A single fixed radius WHPA shall be designated for community water supplies permitted on average to pump less than one hundred thousand (100,000) gpd.

Operators and/or owners of community public water supplies shall provide the county with copies of applications to renew water use/water supply permits issued by the Department of Environmental Protection (formerly the Department of Environmental Regulation) and the Southwest Florida Water Management District. Community water supplies shall be required to provide the county with updates to existing water use/water supply permits. Additionally, water use/water supply permit applications for new wells shall be provided to the county at the time of application to DEP and SWFWMD.

Community water supplies which predate the permit issuance process shall provide a calibrated pump test from which the maximum capacity of the supply can be calculated. Community public water supplies which serve projects ninety-five (95) percent built out and contain adequate flow measuring devices may substitute peak daily pumpage for maximum capacity.

Wellhead Protection Area One

Community public water supplies with average permitted capacity ≥ 100,000 gpd: The land area between the well(s) and the two-year time of travel contour.

Community water supplies with average permitted capacity < 100,000 gpd: The land area encompassed by a 500-foot radius from the well(s).

Wellhead Protection Area Two (2)

Community water supplies with average permitted capacity ≥ 100,000 gpd: The land area between the two- and ten-year time of travel contour.

Community water supplies with average permitted capacity ≤ 100,000 gpd: Not applicable.

(b)

Methodology for the delineation of wellhead protection areas for community water supplies permitted to pump 100,000 gallons per day or greater. The wellhead protection areas correspond to two-and ten-year time of travel contours. These time of travel contours were generated using the WHPA computer model, which was developed for the Environmental Protection Agency. The following is a summary of the procedures used to develop the WHPAs for community water supplies that are permitted on average to pump greater than or equal to (≥) one hundred thousand (100,000) gpd:

(1)

Maps of the potentiometric surface of the Upper Floridan Aquifer, published biannually by the U.S. Geologic Survey, were obtained for May and September 1987, 1988 and 1989. These maps were assumed to represent the range of climatic conditions in Hernando County.

(2)

The direction of regional groundwater flow and hydraulic gradient immediately upgradient of each well or wellfield (referred to as a site) were determined for each of these periods.

(3)

Based on review and analysis of regional groundwater flow direction at each site, two (2) periods were selected for analysis, Period 1 and Period 2. These periods represented the extremes in the direction of groundwater flow to the well(s). All other flow lines for each site were contained within these bounding flow lines.

(4)

Estimated pumping rates for the year 2000 were determined for each well by projecting the population to be served by the water supply by the year 2000 and multiplying this population by the per capita consumption rate determined by the SWFWMD and the affected utilities.

(5)

Aquifer transmissivities were obtained either from observed transmissivity values from an aquifer performance test or they were calculated from the regional flow model and the aquifer thickness. These calculated transmissivities were then converted to hydraulic conductivities.

(6)

An effective porosity value for the Upper Floridan Aquifer was determined to be 0.15.

(7)

The information outlined above was used to calculate the two-and ten-year time of travel zones for each well or wellfield. The methodology is described in the final technical completion report entitled, Development of Wellhead Protection Areas for the Major Public Supply Wells in Hernando County, Florida, herein adopted by reference.

Two (2) delineations were performed for each site, using the data obtained for Period 1 and Period 2 discussed above. An initial WHPA was determined as the composite of the Period 1 and Period 2 zones.

(8)

Final WHPAs for the community public water supplies permitted on average greater than or equal to (≥) one hundred thousand (100,000) gpd were determined as a composite of the initial WHPA described above and a calculated fixed radius based on the two-year time of travel. This was necessitated due to the small distance between the downgradient stagnation point and the well. Due to the nature of the Upper Floridan Aquifer, discontinuities that do not reveal themselves in analysis of the regional flow supply can pose a significant threat to water quality at the well.

(c)

Methodology for the delineation of wellhead protection areas for community water supplies permitted on average to pump less than 100,000 gallons per day. WHPA One for community water supplies permitted on average to pump less than one hundred thousand (100,000) gallons per day shall be a fixed radius of five hundred (500) feet from the well or wells. This radius is based on the average two-year calculated fixed radius developed for the community water supplies permitted on average to pump greater than or equal to (≥) one hundred thousand (100,000) gpd.

(d)

Delineation of special protection areas. Special protection areas (SPAs) shall be designated around vulnerable features which have the potential to discharge directly to the aquifer. These areas include excavations and solution features such as sinkholes and caves. These features shall be deemed vulnerable when they expose the top of the Floridan Aquifer. For purposes of this article, SPA's shall also be designated to include areas with land use approval for mining whether actual excavation has taken place or not. Such a designation as an SPA shall remain in place unless and until any excavation resulting from mining activities is backfilled or otherwise reclaimed as set forth below, or for areas which have not been excavated, the land use approval for mining is eliminated.

The special protection area shall consist of a setback of five hundred (500) feet as measured from the outer boundary of the vulnerable feature or area with land use approval for mining. Special protection areas shall be delineated on the special protection areas map.

Sinkholes or excavations which have been backfilled to the land surface with material of permeability similar to or less than that of the surrounding soil or equivalent reclamation will not be considered a vulnerable feature.

(e)

Rebuttable presumption. Challenge of the county's determination of the applicability of WHPAs and SPAs will be conducted in accordance with the appeal procedure described in this article. The substantially affected party shall provide site-specific data that would allow for more detailed calculations of the zones on a case by case basis.

(f)

Wellhead and special protection area maps:

(1)

Adoption of maps. The WHPA and SPA maps developed by Hernando County are hereby adopted by reference and made a part of this article. Official WHPA and SPA maps shall be placed on digital file at the Hernando County Planning Department.

(2)

Determination of prohibited uses within wellhead and special protection areas. The determination of locations of prohibited uses within the WHPAs and SPAs will be accomplished in one of the following ways:

a.

Acknowledgement by the landowner or operator/owner of the facility that the use as regulated by this article is located within a WHPA or SPA.

b.

Use of global positioning satellite techniques may be used to determine the distance from the protected feature to the prohibited use.

c.

Survey of the proposed location of a prohibited use by a licensed professional surveyor.

If the location of a WHPA or SPA boundary is disputed by any party, a survey, by a licensed professional, shall serve as the basis of the determination.

Potentially prohibited uses located within more than one WHPA shall be considered to be in the most restrictive WHPA. Where the prohibited use is overlapped by WHPAs of different wells or wellfields, the most restrictive WHPA shall apply.

(3)

Review of wellhead and special protection area maps. The WHPA and SPA maps may be reviewed by the board of county commissioners on an annual basis. However, failure to conduct such review will not affect the validity of the existing approved map. Wellhead and special protection area maps may be modified at any time by the board of county commissioners upon notice of an advertised public hearing for changes in technical knowledge, such as transmissivity or porosity; changes in pumping rates; reconfiguration of wellfields; the installation of new wells or wellfields; and to accommodate changes in topography, such as sinkholes or newly approved mining areas, in a manner consistent with the methodology and standards established in this article for designation of these areas. In the event that new wellfields are established within Hernando County which result in wellhead protection areas being established pursuant to the methodology set forth in this article, or changes occur with respect to special protection areas, the WHPA and SPA maps may be amended by board resolution to reflect the existence of such wellhead protection areas or changes in special protection areas. Any substantially affected person may petition the board to consider amendments to the WHPA and SPA maps. The county shall schedule the requested WHPA or SPA map amendment no more than sixty (60) days after receipt by the county of the request.

(Ord. No. 94-8, § 5, 6-27-94)