Underground
Injection Control Program
The Department of Environmental Protection's Underground
Injection Control (UIC) program consists of a team of geologists and engineers dedicated
to protecting the State of Florida's underground sources of drinking water
(USDW) while
maintaining the lawful option of disposal of appropriately treated fluids via underground injection wells. A USDW is
defined as an aquifer that contains a total dissolved solids concentration of less than
10,000 milligrams per liter. The UIC program also is dedicated to preventing degradation of the
quality of other aquifers adjacent to the injection zone. Subsurface injection, the
practice of emplacing fluids in a permeable underground aquifer by gravity flow or under
pressure through an injection well, is one of a variety of wastewater disposal
or reuse methods used in
Florida. The five classes of injection wells:
- Class I
Wells used to inject hazardous waste (new hazardous waste wells were
banned in 1983), nonhazardous waste, or municipal waste below the lowermost USDW.
- Class II
Wells used to inject fluids associated with the production of oil and natural gas or
fluids used to enhance hydrocarbon recovery.
- Class III
Wells which inject fluids for extraction of minerals (none in
Florida).
- Class IV
Wells or septic systems which are used to dispose of hazardous or radioactive wastes into
or above a USDW. (Banned in Florida.)
- Class V
Wells not included in the other well classes which generally inject nonhazardous fluid
into or above a USDW.
There are more than 125 active Class I wells in Florida. The
majority of the Class I injection facilities in Florida dispose of non hazardous,
secondary-treated effluent from domestic wastewater treatment plants. At locations where hydrogeologic conditions are suitable and where other disposal methods are not possible or
may cause contamination, subsurface injection below all USDWs is considered a viable
and lawful disposal method. There are favorable hydrogeologic conditions in Florida where the
underground formations have the natural ability to accept and confine the waste.
See an illustration of a
Class I
municipal well. The
injection wells are required to be constructed, maintained, and operated so that the
injected fluid remains in the injection zone, and the unapproved interchange of water
between aquifers is prohibited. Class I injection wells are monitored so that if migration
of injection fluids were to occur it would be detected before reaching the USDW. Testing
is conducted on all Class I injection wells at a minimum of every five years to determine
that the well structure has integrity. For the location and
permitting status of Class I wells in Florida as of November 2003, please see
the Class I map
and Class I table.
(We are trying to improve on the resolution of the map; we appreciate your
patience.) As of November 2003, the average daily flow for these wells was a
little more than 361 million gallons per day; this flow is graphically
represented by county.
- Class II injection wells are regulated by the Department of
Environmental Protection,
Florida Geological Survey, Oil and Gas Section.
- Class III wells are injection wells associated with the
extraction of minerals. There are no Class III wells in Florida.
- Class IV injection wells have been banned in Florida since
1982.
- Class V injection wells are wells not included Classes I
thru IV. Class V wells are used for the storage or disposal of fluids into or above a
USDW. The fluid injected must meet appropriate criteria as
determined by the classification of the receiving aquifer. Common types of
Class V wells include air conditioning return flow wells, swimming pool
drainage wells, stormwater drainage wells, lake level control wells,
domestic waste wells, and aquifer storage and recovery (ASR) wells (see
below). There are more than 8000 Class V wells in Florida.
Financial Responsibility
The UIC program requires applicants for Class I wells to assure, through a
performance bond or other appropriate means, that resources necessary to cover
post-closure monitoring and any corrective action resulting from this
monitoring are available. [See s. 62-528.435(9) in the UIC
rule.] Guidance
on fulfilling the financial responsibility requirements is set forth in the
document, "Financial Responsibility Options for Owners and Operators of Injection Wells".
(This document has been scanned from an old source that has not yet been
converted electronically. The information is current. If you have difficulty
reading the guidance, please call the UIC program at 850.245.8644 and we will
be happy to provide a hard copy.) One financial responsibility option for
local governments only is set forth in the
Local Government
Guarantee document.
Aquifer storage and
recovery (ASR)
Aquifer storage and
recovery (ASR) is a mechanism for storing water underground through an injection well to be withdrawn in the future, through the same well, for beneficial purposes. Typically, water
is stored during times of excess supply for use when supplies are limited. ASR wells are capable of storing treated drinking water as well as
treated or raw surface or groundwater. However, whether treated or not,
water injected into ASR wells must meet Florida's drinking water quality
standards. The level of treatment required after storage depends on the use of the water, whether for public consumption, surface water augmentation, wetlands enhancement, irrigation, saltwater intrusion barrier, etc. Because ASR provides for the storage of water that would otherwise be lost to tide or evaporation, it represents a crucial water supply management strategy for Florida’s future.
See a simplified depiction of an
ASR
well.
For the location and
permitting status of ASR wells in Florida as of November 2003, please see the
ASR map and
ASR table. (We are
trying to improve on the resolution of the map; we appreciate your
patience.)
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