§ 62-3774. General conditions.

(a)

No individual within the county shall:

(1)

Attach a new or modified water-source heat pump to an existing artesian well;

(2)

Replace an existing water-source heat pump unit now utilizing an artesian well;

(3)

Drill an artesian well for use by water-source heat pump unit;

(4)

Drill a new artesian well for an existing water-source heat pump unit;

Unless said heat pump unit is equipped with a second well of equal or greater depth so that water withdrawn can be returned to the aquifer of origin. This division does not prohibit the use of water from either well for irrigation purposes.

(b)

Prior to December 1, 1986, all existing water-source heat pump units using an artesian well which do not have a return well of equal or greater depth shall be required to have in operation a demand valve which prevents the flow of water from the well when the heat pump unit is not in operation.

(c)

All water-source heat pump units which withdraw water from an artesian well shall install or utilize a second well of equal size and equal or greater depth for the purpose of returning the water to the aquifer of origin, when the heat pump unit is being replaced.

(d)

Water-source heat pump units withdrawing water from the surficial aquifer system may be installed as a single well system if it is an open recharge system, where the discharge is used for irrigation and percolation capacity is available to absorb peak daily discharge within the boundaries of the individual's lot. Where percolation capacity is not available, an open-loop or closed-loop system will be required.

(e)

Injection well standards.

(1)

All open-loop injection systems, including a supply and return well pair, shall be required to have a minimum spacing of 50 feet for new low density single-family residential structures, or those systems under 15 gallons per minute, or those systems under five tons' designed air conditioning load. All other open-loop systems shall follow the minimum horizontal spacing requirements as presented in Table I, made part hereof, for the identified source aquifer. This spacing requirement shall include any wells on the applicant's or adjacent property owner's land. Spacing requirements of 100-F, Florida Administrative Code, or applicable county health codes supersede this standard if more stringent.

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TABLE I
MINIMUM HORIZONTAL SPACING
BETWEEN INJECTION WELL AND SUPPLY WELL
FOR FLORIDAN AQUIFER (ARTESIAN) INSTALLATIONS

240 Days*		Flow, in Gallons Per Minute
Length of borehole of injection wall, in feet		5	10	15	20	25	30	35	40	45	50	55	60	65	70	75
	50	Minimum   50 ft.   Spacing   Required		95	110	122	134	145	155	164	173	182	190	198	205	212
	75			77	89	100	110	118	126	134	141	148	155	161	167	173
	100			67	77	87	95	102	110	116	122	128	134	140	145	150
	125			60	69	77	85	92	98	104	110	115	120	125	130	134
	150			55	63	71	77	84	89	95	100	105	110	114	118	122
	175			52	58	65	72	77	83	88	92	97	101	105	109	113
	200				55	61	67	71	77	82	87	91	95	99	102	106

 

*Assumption of 8 month use for cooling node.

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(2)

Injection well capacity shall equal or exceed 150 percent [of] the design capacity requirements of the water-source heat pump system.

(3)

The injection system of an artesian well shall be designed to provide adequate injection pressures to overcome recorded maximum natural artesian head where present.

(4)

If natural artesian pressure does not exist, a drop-pipe is required. Pressurization of the injection line and drop-pipe shall be done by using a spring-loaded check valve installed in reverse. To obtain the proper setting, adjust the spring as follows:

Water level (static) × 0.43 ° 10 psi or use the following table:

Depth to Static Water Level (Feet)	Spring Release Pressure (psi)
0	10
10	14
20	18
30	23
40	27
50	31
60	36
70	40
80	45
90	49
100	53

 

The drop-pipe shall extend below the lowest yearly water level of the well, where the water level is at or below land surface.

(5)

Thermal re-injection limits shall be 15 degrees C. (59 degrees F.) for the heating mode and 35 degrees C. (95 degrees F.) for the cooling mode.

(6)

Maintenance programs such as backflushing and well stimulation of the injection well should be scheduled periodically to reduce pressure build-up and to optimize the thermal exchange characteristics of the well. Well stimulation techniques refer to, but are not limited to, those in § 17-28.12(56) Florida Administrative Code. A licensed water well contractor is required unless prior approval is given by the division.

(7)

All injection wells shall be drilled by licensed water well contractors and permitted where required by the St. Johns River Water Management District, Chapter 40C-3, Florida Administrative Code, or the Florida Department of Environmental Regulation as a Class V injection well, pursuant to Chapter 17-28, Florida Administrative Code, prior to construction.

(8)

Injection wells will be completed to the aquifer and zone of origin unless otherwise directed by the division; open bore holes shall be a minimum of 50 feet.

(9)

System water flows shall not exceed three gallons per minute per ton of air conditioning load installed. A fixed oriface flow device on the discharge side shall be installed to limit the flow as required.

(10)

All open-loop or single-well systems, where authorized, shall have a demand valve to stop the flow of water when the water-source heat pump is not operating. Multipurpose well systems may have a multiple-pump design if a pump shut-off device is necessary to allow withdrawals during heat pump shut-down.

(11)

Well casings shall be completed at or above grade to allow vertical access for maintenance of section procedures in accordance with Chapter 17-21, Florida Administrative Code.

(12)

All wells shall be disinfected prior to operation to prevent cross-contamination between zones or plumes of the aquifer strata producing supply water either identified or unknown.

(f)

Earth-coupled closed-loop borehole standards.

(1)

Vertical boreholes shall be spaced a minimum of 15 feet apart. Horizontal trenches shall be spaced a minimum of six feet apart and tubing will be separated by two feet at four and six feet below grade.

(2)

Boreholes shall be sealed with grout in accordance with Chapter 40C-3.5.17, Florida Administrative Code.

(3)

No additives to the circulating fluid will be approved for placement in either vertical or horizontal earth-coupled closed-loop installations.

(4)

All loops shall be pressure-tested prior to final job completion.

(5)

All vertical boreholes shall be installed by licensed water well contractors.

(g)

No individual shall use a public water supply system to operate a new or modified water-source heat pump unit.

(Ord. No. 85-33, § 4, 10-8-85; Ord. No. 86-16, § 2, 8-5-86)