Florida passed House Bill 1379 in 2023, becoming the first state in the U.S. to require nitrogen-reducing septic systems by law across large parts of the state. The law targets nutrient pollution — primarily nitrogen from conventional septic systems — that has degraded springs, rivers, and coastal lagoons across Florida for decades.
If your property is in a BMAP area or impacted zone, you may face a mandatory upgrade by July 1, 2030. If you're installing a new system now, you may already be required to use an enhanced nutrient-reducing system. The answer depends entirely on where your property is located.
Why HB 1379 Was Passed
Conventional septic systems do a reasonable job of treating solids and pathogens, but they are not designed to remove nitrogen. Effluent from a standard septic system enters the drain field and percolates into groundwater carrying 30–70% of the original nitrogen load, depending on soil type and depth to the water table.
Florida has roughly 2.7 million onsite septic systems — the most of any state. In areas where those systems are concentrated near sensitive waterways, the cumulative nitrogen input fuels algae blooms that consume oxygen, kill fish, and choke out seagrass beds. The Indian River Lagoon — once one of the most biodiverse estuaries in North America — lost over 58,000 acres of seagrass between 2011 and 2019, partly attributed to nutrient loading from surrounding development.
HB 1379 attempts to address this by requiring Enhanced Nutrient Reducing systems (ENR-OSTDS) — those that achieve at least 65% nitrogen reduction — wherever cleanup plans (BMAPs) are already in effect.
Who HB 1379 Affects
The law applies within BMAP areas and Alternative Restoration Plan areas — not all of Florida
HB 1379 applies to properties within two types of impacted areas:
- Basin Management Action Plan (BMAP) areas — officially designated cleanup plans for impaired water bodies, including springs, rivers, and estuaries. BMAPs cover portions of most Florida counties.
- Alternative Restoration Plans (ARP) areas — smaller-scale restoration zones for water bodies that don't yet have a full BMAP but are on a cleanup pathway.
The following 10 counties have no impacted areas under HB 1379 and are completely exempt: Bay, Calhoun, Franklin, Gulf, Holmes, Liberty, Nassau, Santa Rosa, Walton, and Washington. Every other Florida county contains at least some impacted parcels.
Being in an "impacted county" does not mean your specific parcel is in an impacted zone.
BMAP boundaries follow watershed lines, not county lines. A homeowner in Marion County might be
inside a Silver Springs BMAP Priority Focus Area; a neighbor half a mile away might not be.
The only way to know for certain is to check the
Florida DEP's BMAP mapping tool at floridadep.gov with your specific address.
Key Dates and What They Require
July 1, 2023 — New Systems on Small Lots
Any application for a new septic system on a lot of one acre or less within an impacted area must now install an ENR-OSTDS instead of a conventional system. If sewer is available at the property, connection to sewer is required instead.
January 1, 2024 — Indian River Lagoon Area, All Lot Sizes
For properties within the Indian River Lagoon Protection Program area — covering parts of Brevard, Indian River, St. Lucie, and Volusia counties — the ENR requirement applies to all lot sizes for new systems, not just lots under one acre.
December 15, 2025 — Repairs in Citrus and Hernando County Springs BMAPs
Any septic repair or modification permit filed on or after December 15, 2025 within the Weeki Wachee, Homosassa, and Chassahowitzka Springs Group BMAP Priority Focus Areas must include a nitrogen-reducing design. This is notable because it extends ENR requirements beyond new construction to routine repairs within those specific springs watersheds.
July 1, 2030 — Existing Systems in All Impacted Areas
This is the major deadline. By July 1, 2030, any existing conventional septic system on a property within an impacted area must either:
- Connect to central sewer (if available), or
- Upgrade to an ENR-OSTDS or other system achieving at least 65% nitrogen reduction
This applies to both residential and commercial properties. There is no exemption for age of the system, lot size, or owner-occupied status. A conventional system that was installed in 2010 and is functioning perfectly still must be upgraded or connected to sewer by 2030 if the property is within the impacted area.
The Three Types of ENR Systems
Three system types qualify as ENR-OSTDS under HB 1379, all of which achieve at least 65% nitrogen reduction:
1. In-Ground Nitrogen-Reducing Biofilter (INRB)
A passive system installed between the septic tank and the drain field. Effluent passes through a media-filled chamber where biological and chemical processes remove nitrogen before reaching the soil. INRBs require no electricity and have minimal moving parts — maintenance is simpler than an ATU. They depend on soil conditions and site geometry; not all sites can accommodate them.
2. NSF 245-Certified Aerobic Treatment Unit (ATU)
An active system with an air pump that forces oxygen into the treatment chamber, supporting aerobic bacteria that aggressively break down nitrogen. ATUs are more common in retrofit situations where site space is limited. They require electricity (typically $5–$15/month), and Florida law requires a maintenance contract — typically $100–$250/year — for periodic inspection, filter cleaning, and alarm response. Breakdowns can trigger permit violations if not addressed promptly.
3. Performance-Based Treatment System (PBTS)
A catchall category for systems not covered by the INRB or ATU classifications — typically engineered or hybrid systems approved on a case-by-case basis. These are less common and generally used in unusual site conditions or for commercial properties. Approval requires documentation of 65% nitrogen reduction performance.
Which system type is right for a given property depends on lot size, soil type, depth to groundwater, and the space available for installation. A licensed septic contractor or environmental engineer can assess your site and recommend the appropriate system. Not all contractors are licensed for ENR installations — verify that any contractor you hire holds the appropriate Florida certification for the system type.
Cost to Upgrade and Financial Assistance
Average upgrade cost: ~$20,000 — but grants in many counties offset a significant portion
Upgrading a conventional system to an ENR-OSTDS is not cheap. The average cost across Florida is approximately $20,000 for an existing system, which includes permitting, excavation, system installation, and inspection. Costs vary by system type (ATUs generally cost more than INRBs), site conditions, and contractor rates in your area.
Several counties and state programs offer financial assistance:
| County/Program | Grant Amount | Notes |
|---|---|---|
| Citrus County, FL | Up to $7,000 | Septic Upgrade Incentive Program; first-come, first-served |
| Volusia County, FL | Up to $14,000 (ATU) / $8,000 (INRB) | Septic Upgrade Incentive Program; Indian River Lagoon area |
| Brevard County, FL | Min. $6,000 | Save Our Indian River Lagoon; all IRL area properties eligible |
| Florida State (DEP) | $100M statewide allocated | Supports sewer conversion + pollution reduction projects; distributed via counties |
Grant programs operate on a first-come, first-served basis and are funded until depleted. Homeowners who wait until 2029 to start the process may find no grant funding remains and face a longer permitting queue as the 2030 deadline approaches. Contact your county's environmental services department to ask about active programs and eligibility requirements.
How the Law Applies in Common Florida Counties
Citrus County, FL
Most of Citrus County falls within the Weeki Wachee, Homosassa, and Chassahowitzka Springs BMAPs. As of December 15, 2025, septic repair and modification permits within Priority Focus Areas must include nitrogen-reducing designs. The county offers up to $7,000 in reimbursements through its Septic Upgrade Incentive Program. Homeowners near the Nature Coast springs should verify their parcel status and apply for grant funding early.
→ Find septic contractors in Citrus County, FLMarion County, FL
Marion County contains the Silver Springs BMAP area, one of the most nitrogen-impaired first-magnitude springs in Florida. Properties within the Silver Springs watershed are in an impacted area under HB 1379. Marion County also completed its transition to Florida DEP septic permitting on July 1, 2025 — permits are no longer processed through the county health department.
→ Find septic contractors in Marion County, FLAlachua County, FL
Alachua County includes portions of the Santa Fe River BMAP and areas draining to impaired springs. The county is home to a high concentration of rural septic systems near sensitive springs areas. Check the DEP mapping tool to determine whether your specific parcel is within an impacted area.
→ Find septic contractors in Alachua County, FLPasco County, FL
Pasco County includes areas within the Weeki Wachee Springs BMAP and other impacted zones. Portions of Pasco County drain to the Withlacoochee River system as well. As with other counties, the ENR requirement applies at the parcel level — not all of Pasco is impacted.
→ Find septic contractors in Pasco County, FLWhat to Do If You Think You're Affected
- Check the DEP BMAP mapping tool. Go to
floridadep.gov/water/onsite-sewageand use the BMAP and Alternative Restoration Plans mapping tool to enter your address and confirm whether your parcel is in an impacted area. Your county property appraiser's parcel number is helpful for this search. - Confirm your system type. If you don't know whether you have a conventional system or an ENR-approved system, check the permit on file with your county health department or the Florida DOH. Systems installed after July 2023 in impacted areas should have been permitted as ENR systems.
- Get a site assessment. If you're in an impacted area and have a conventional system, contact a licensed septic contractor to evaluate your site for ENR upgrade options. Site conditions determine whether an INRB or ATU is appropriate and affect total cost.
- Apply for grant funding early. Contact your county's environmental services department to ask about current Septic Upgrade Incentive Program availability. Funding is limited and programs are first-come, first-served.
- Don't wait until 2029. Permitting, site assessment, installation, and inspection typically take 3–6 months under normal conditions. As the 2030 deadline approaches, backlogs will grow and grant funding will thin. Starting in 2026 or 2027 is significantly less risky than waiting.
Common Questions
Does Florida's new septic law (HB 1379) affect my property? ▾
It depends on your location. HB 1379 applies to properties within Basin Management Action Plan (BMAP) areas and Alternative Restoration Plan areas — places where water bodies are impaired and a cleanup plan is in effect. Most Florida counties contain at least some impacted area. Only 10 counties have no impacted areas at all: Bay, Calhoun, Franklin, Gulf, Holmes, Liberty, Nassau, Santa Rosa, Walton, and Washington. The Florida DEP maintains a free online mapping tool where you can enter your address to check whether your specific parcel is in an impacted zone.
What is the deadline to upgrade an existing septic system under HB 1379? ▾
July 1, 2030. By that date, any property with an existing conventional septic system located within an impacted area must either connect to central sewer (if available) or upgrade to an Enhanced Nutrient Reducing system (ENR-OSTDS) that achieves at least 65% nitrogen reduction. This deadline applies to both residential and commercial properties.
How much does it cost to upgrade to an ENR septic system in Florida? ▾
The average cost to upgrade an existing conventional system to an ENR-OSTDS is approximately $20,000, though costs vary by system type and site conditions. Several Florida counties offer grant or reimbursement programs to offset these costs. Citrus County offers up to $7,000; Volusia County offers up to $14,000 for ATU systems or $8,000 for INRBs; Brevard County offers a minimum $6,000 grant through its Save Our Indian River Lagoon program. These programs are first-come, first-served and subject to available funding — homeowners in impacted areas should apply sooner rather than later.
What is the difference between an INRB and an ATU (aerobic treatment unit)? ▾
Both are ENR-approved systems under HB 1379. An in-ground nitrogen-reducing biofilter (INRB) is a passive system installed between the septic tank and drain field that filters effluent through a media bed where biological processes remove nitrogen. An aerobic treatment unit (ATU) is an active system that injects air into the treatment chamber to support aerobic bacteria that break down nitrogen more aggressively. ATUs typically cost more to install and require ongoing maintenance contracts (often required by the Florida DOH permit). INRBs are simpler and lower-maintenance but depend on soil conditions. Your site conditions and county requirements will influence which system is appropriate.
I'm in Citrus County. Does HB 1379 apply to me? ▾
Most of Citrus County is in impacted areas covered by the Weeki Wachee, Homosassa, and Chassahowitzka Springs Group BMAPs. As of December 15, 2025, any septic repair or modification permit application within those Priority Focus Areas must include a nitrogen-reducing design. For new systems, ENR requirements apply to lots one acre or less. Citrus County offers a Septic Upgrade Incentive Program that provides reimbursements of up to $7,000 for eligible homeowners.
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