Aquifer Exemption Criteria
[Rule 62-528.300, F.A.C.]
NOTE: The following technical requirements were developed by the Department and EPA and are to be used as guidance in reviewing an aquifer exemption petition. Although not directly referred to in state rule or federal regulation the following items are needed in order for the Department and EPA to determine if the aquifer exemption criteria in Rule 62-528.300(3), F.A.C., and 40 CFR 146.4 have been satisfied.
1. The exemption request must demonstrate that the aquifer does not currently serve as a source of drinking water. To demonstrate this, the applicant should survey the proposed exempted area to identify any water supply wells which tap the proposed exempted area. The aquifer exemption request should cover any portion of the aquifer(s) into which injected fluids are expected to migrate as well as any aquifer(s), or portion(s) thereof, where formation fluid quality will be significantly altered due to injection, and a buffer zone of at least one-quarter mile beyond the area. The exemption request should cover the smallest area that will satisfy these requirements. A search should be made of all public records for water supply wells. In addition, attempts should be made to verify the presence or absence of water supply wells. Any water supply wells located should be identified on the map showing the proposed exempted area. The use (e.g. private drinking water supply, public supply, irrigation, etc.), size and depth of all water supply wells should be noted on the map. Water supply wells which penetrate the aquifer or portion which is to be exempted should be noted. If there are no water supply wells that would be affected by the exemption, the request should state that a survey was conducted, how it was conducted, and that there are no water supply wells located within the proposed area which tap the aquifer to be exempted. The location of the injection wells should also be shown on the same map.
2. A narrative description of the proposed exemption plus illustrations, maps, or other means that describe in geographic, and/or geometric terms (such as vertical and lateral limits and gradient) which are clear and definite, the aquifer(s) or parts thereof that satisfy the exemption criteria.
3. A written description of the aquifer or portion thereof that is to be exempted including:
a) Geologic name(s) of the designated aquifer(s) or description, if name is not available,
b) Stratigraphic information,
c) The general name applied to the aquifer(s) if the aquifer(s) consists of one or more formations or groups,
d) Precise definition of the upper and lower boundaries of the proposed aquifer exemption, i.e., the contact with a certain confining zone,
e) A map showing contours of the elevation (referenced to NGVD 1929) of the top and base of the aquifer, or portion thereof, which is to be exempted,
f) An isopach map of the confining unit overlying, and where applicable, underlying the aquifer, or portion thereof, which is to be exempted,
g) An isopach map of the aquifer, or portion thereof, which is to be exempted,
h) Area of the exemption (e.g., acres, square miles, etc.),
i) Water quality analysis of the aquifer(s) to be exempted (if proposed exemption is a large area, water quality analyses may be required from several locations within the proposed exemption),
j) A stratigraphic column(s) to the base of the Floridan aquifer illustrating all known formations, their lithology, thickness, depth and any water bearing zones or aquifers. The water quality and primary use of all water bearing zones should also be noted, and
k) A cross-section showing the depth at which the 3000 and 10,000 mg/L TDS concentration is encountered throughout the exempted area.
4. A map of appropriate scale should be submitted which shows the boundaries of the exemption request and any cultural or geographical features in the area. A 1:24,000 USGS topographic quadrangle is acceptable. However, if the proposed exempted area is large a scale of up to 1:63,360 may be used. All wells within the proposed exemption area boundaries should be identified. Construction specifics and ground water quality information for all wells within the proposed exempted area should be included.
5. The size of the aquifer portion to be exempted should, at a minimum, take into account the following factors:
a) Pressure in the injection zone (if applicable),
b) Total fluid volume to be injected during the life of the facility,
c) Injected fluid characteristics,
d) Chemistry of the native formation fluid prior to any injection,
e) Estimates of the effective migration distance possible from the injection well,
f) Location of the 3,000 mg/l TDS interface,
g) Volume of fluid to be recovered on an annual basis (aquifer storage and recovery projects), and
h) Probability based on modeling that the injected fluids or their alteration products will exceed the proposed exempted
6. Information should be submitted regarding the quality and availability of water from the aquifer proposed for exemption. Also, the exemption request must analyze the potential for public water supply use of the aquifer. This may include a description of current sources of public and private water supply in the area, a discussion of the adequacy of current water supply sources to supply future needs, population projections, economy, future technology, and a discussion of other available water supply within the area.
7. The exemption request must also include a comprehensive consideration of the environmental issues and impacts. The study must address the environmental impact of the action, possible adverse environmental effects, the relationship between the long-term uses and goals, and any irreversible commitment of resources.
Although not specifically addressed in the state or federal regulations concerning aquifer exemptions, the following information should also be supplied with the aquifer exemption petition:
8. For aquifer storage and recovery projects, a description of the test procedure should be included in the exemption request. This discussion should include:
a) Injection fluid:
i. Volume of fluid which is to be injected on a monthly and annual basis,
ii. Source of fluids which are to be injected,
iii. Water quality of the fluids which are to be injected;
b) Fluid to be recovered:
i. Volume of fluid which is to be recovered on a monthly and annual basis,
ii. Uses for the recovered fluids (e.g. drinking water, agricultural irrigation),
iii. If the fluids recovered are not to be used by the ASR permittee, a list of potential users and those committing to use the recovered water;
c) Length of time between a typical injection and recovery cycle and the ratio of annual injected volume versus annual recovered volume;
d) Monitoring program; and
e) Purpose of the ASR project.
NOTE - In order to be considered as an ASR project a significant amount of the fluids injected must be recovered on an annual basis. Other projects may be permitted as experimental technologies or other Class V well types depending on the source of the injected fluids.
9. The exemption request should address possible alternatives to injection. This discussion should include a ranking of all alternatives considered including injection based on environmental and financial factors.
Last updated: January 02, 2013
D.E.P. Southwest District - TAMPA
13051 N. Telecom Parkway Temple Terrace, Fl. 33637 Phone: 813-632-7600 Fax: 813-632-7665
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