15.2 Water Wells, Pumps & Irrigation Systems

Water Wells, Pumps & Irrigation Systems

Wells, pumps and irrigation involve distinct responsibilities for well construction, potable-water equipment and cross-connection protection. This section develops those relationships as supplemental learning, without assigning a state contractor blueprint weight to the local journeyman examination.

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1. Private Water Wells

Who Regulates What

• Well construction and the well contractor's license are regulated by the water management districts under delegation from FDEP, through FAC Chapters 62-524, 62-531 and 62-532. Drilling, casing, grouting, and well abandonment are water well contractor work.
• The plumbing side of the system — the pump, the pressure tank, the piping into the house, and the cross-connection protection — is FPC Section 614, Well Pumps and Tanks Used for Private Potable Water Systems.
• Onsite sewage setbacks to the well come from the onsite sewage rule covered in Section 14.1: Current Rule 62-6.005 gives ordinary distances of 75 feet to a private potable/multifamily well, 50 feet to a nonpotable well, and 100 feet to the specified public-well category at up to 2,000 gpd or 200 feet above it. Historical-lot and other expressly authorized exception routes require separate eligibility review; they are not blanket reductions for a new system.

Well and Pump Terminology

At approximately 14.7 psia atmosphere and 0.433 psi per foot of water, the ideal atmospheric column is about 34 feet. Vapor pressure, suction losses and required net positive suction head reduce usable lift; roughly 25 feet is a common practical illustration, not a universal pump limit. Use the selected pump’s performance and site conditions to choose shallow-well, downhole jet or submersible equipment.

FPC Section 614 — Pumps

614.1 Pumps: well pumps used for potable water shall comply with 614.1.1 and 614.1.2.

Table 614.1 — Minimum Private Potable Water System Pump Size

The table's notes add that the values are averages that do not include higher or lower extremes, and that installations over six bathrooms shall be approved by the code official.

614.1.1 Pump Installation: pumps shall be installed for operation without repriming or breaking suction, and shall be connected to the well head by a union, companion flange or compression coupling so the pump is accessible for maintenance, repair and removal. A pump hard-piped to the casing has to be cut out to be serviced.

614.1.2 Pump Sizing: minimum pump size shall be determined by Table 614.1.

FPC Section 614.2 — Pressure Tanks

Tanks shall rely on expansion of a flexible membrane within a restricting container, or be direct water-to-air interface tanks. Every pressure tank storing potable water under pressure shall be identified by seal, label or plate showing the manufacturer's name and model number, shall be constructed of steel, fiberglass or comparable materials, and shall meet this sizing rule:

Pressure tank drawdown shall be a minimum of 1 gallon for every gallon per minute produced by the pump. Exception: pump start applications, constant pressure devices and variable speed pumps.

Worked example. A three-bathroom home takes a 17 gpm pump from Table 614.1. Section 614.2 then requires a pressure tank with at least 17 gallons of drawdown — not 17 gallons of tank volume. Assume a conventional pump outside the stated exceptions. Use the manufacturer’s drawdown chart at the actual precharge and cut-in/cut-out settings. In a supplied chart example, drawdown is 27% of nominal volume: 17/0.27 = 62.96 gallons nominal, so a candidate must provide at least 17 gallons actual drawdown at those settings. This is not a universal tank-volume ratio or a predicted failure deadline.

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2. Turf and Landscape Irrigation

Florida publishes FBC-Plumbing Appendix F, Proposed Construction Building Codes for Turf and Landscape Irrigation Systems. Under FBC-Building 101.2.1, appendix provisions are not mandatory unless specifically adopted. The Appendix F permit, material and installation rules below apply where that appendix has been adopted or incorporated into the approved project requirements; they are not asserted as automatically mandatory statewide. Body-code provisions such as FPC 318.1 and 608 remain separate. Its stated purpose is uniform minimum standards for safe, cost-effective, reliable systems that promote the efficient use and protection of water and other natural resources. It applies to residential and commercial landscape areas, and expressly does not apply to golf courses, nurseries, greenhouses or agricultural production systems.

Permits and Submittals

• A permit is required to construct, enlarge, alter, modify, repair or move any irrigation system, or install or alter regulated equipment. No permit is required for general maintenance or repairs that do not change the structure or alter the system and whose value does not exceed $600 in labor and material based on invoice value — but exempt work still has to comply with the code.
• Single-family residence: design or shop drawings to reasonable scale showing the entire site and improvements, which may be prepared by a properly licensed qualified contractor.
• Commercial, industrial, municipal and multiple-family: professionally designed drawings showing date, scale, revisions, legend, specifications, water source, meter or point of connection, backflow prevention devices, pump station size and location, design operating pressure and flow rate per zone, precipitation rate per zone, and locations of pipe, controllers, valves, sprinklers, sleeves and gate valves.

The One-Foot Rule

FPC Section 318.1, Irrigation, is a Florida amendment and it is short: "Irrigation/sprinkler systems and risers for spray heads shall not be installed within 1 foot (305 mm) of the building sidewall." Keeping spray off the wall protects the termite treatment zone and the wall finish; its body-code requirement is separate from the conditional appendix provisions.

Materials (Appendix F Part IV)

• PVC pipe complying with ASTM D1785, ASTM D2241, AWWA C900 or AWWA C905. SDR-PR pipe shall have a minimum wall thickness as required by SDR-26. Solvent-weld fittings shall meet at minimum Schedule 40 per ASTM D2466; threaded PVC fittings Schedule 40 per ASTM D2464; gasketed fittings ASTM D3139 with ASTM F477 gaskets.
• Steel pipe shall be Schedule 40 or greater, hot-dipped galvanized or black to ASTM A53, with Schedule 40 malleable iron threaded fittings.
• Polyethylene flexible swing joints shall be thick-walled with a minimum pressure rating of 75 psi per ASTM D2239.
• Valves shall have a maximum working pressure rating not less than 125 psi, waivable for low mainline pressure systems at 30 psi or less.
• All pipe, sprinklers, valves and valve boxes used with effluent (reclaimed) water shall be designated for nonpotable use by label or by the industry standard color purple, and hose connections shall not be provided on nonpotable irrigation systems.

Installation (Appendix F Part V)

Depth of cover where Appendix F applies uses two distinct nominal-diameter tables. Do not force the unequal ranges into shared rows.

Other provisions within the adopted/applicable Appendix F scope:

• Thrust blocks must be used on all gasketed PVC systems, formed against a solid, hand-excavated trench wall undamaged by mechanical equipment, constructed of concrete filling the space between pipe and trench to the height of the pipe's outside diameter, and sized per ASAE S-376.1.
• Initial backfill shall be free from rocks or stones larger than 1 inch, and blocking or mounding shall not be used to bring pipe to final grade.
• Pipe sleeves under pavement shall be two pipe sizes larger than the carrier pipe (or twice the diameter of the wire bundle), extend at least 3 feet beyond the paved area or as required by FDOT, and have a wall thickness at least equal to Schedule 40 or PR 160, whichever is thicker.
• Valve boxes: the appendix says the top of the valve body should have at least 6 inches of cover in nontraffic/noncultivated areas and 18 inches in traffic areas; these are recommendations, distinct from its mandatory pipe-cover table; boxes shall not rest on the pipe and shall sit flush with grade.
• Sprinkler separation: at least 4 inches between sprinklers and pavement, and at least 12 inches between sprinklers and buildings and other vertical structures. The installation text says sprinklers should be adjusted to avoid unnecessary discharge on pavements and structures; it directs adjustment away from roads. Its final-inspection provisions require adjustment to minimize overspray, with minor prevailing-wind tolerances. Do not convert every “should” into “shall.”
• Pop-up height shall clear the turf: 6 inches for St. Augustine, Zoysia and Bahia; 4 inches for Bermuda, Centipede and Seashore Paspalum.
• Low-voltage wire: minimum #14 AWG single-strand control wire except on single-lot residential systems, buried at least 12 inches where not directly under the mainline, with white reserved for common wires, UL-approved direct-burial connectors, and all splices enclosed within a valve box.
• Rain switch: mounted on a stationary structure with a minimum 5-foot clearance from other outdoor equipment, clear of tree canopy and overhead obstructions, and above the height of sprinkler coverage. Soil moisture and evapotranspiration sensors are installed and monitored per manufacturer guidance under FS Section 373.62.

Backflow Protection — The Critical Item

Appendix F Part II requires backflow prevention assemblies at all cross connections with all water supplies, in accordance with county, municipal or other applicable codes, and adds the tiebreaker: "In the event of conflicting regulation provide the assembly type which gives the highest degree of protection."

For chemical injection the requirement hardens:

• Systems into which chemicals are injected shall conform to FS Sections 487.021 and 487.055 and to EPA Pesticide Regulation Notice 87-1.
• For municipal water supplies, chemical injection equipment must be separated from the water supply by an approved air gap separation or a reduced pressure principle assembly approved by the Foundation for Cross-Connection Control and complying with ASSE 1013, protecting against both back-siphonage and back-pressure.
• For other supplies, Florida law, EPA regulations or local codes apply, and in the absence of legal guidelines at least a pressure vacuum breaker should be used.

Separate body-code requirement: FPC 608.17.5 requires irrigation backflow protection and a reduced-pressure-principle assembly where chemicals are introduced. Any air-gap supply must be an approved complete separation arrangement; a downstream vacuum breaker is not a substitute for chemical/backpressure protection.

On the building side, the hose bibb used to feed a portable sprinkler is covered by FPC Section 608.16.4.2, which requires sillcocks, hose bibbs and wall hydrants to be protected by an atmospheric-type or pressure-type vacuum breaker or a permanently attached hose connection vacuum breaker, and FPC Section 608.16.4 sets the critical level of a pipe-applied vacuum breaker not less than 6 inches above the flood level rim of the fixture, receptor or device served.