FDEP-Approved Nitrogen-Reducing Septic Systems: The 2026 PBTS List Designers Use

By The Complos Team. Last reviewed 2026-05-14.

TL;DR. The FDEP PBTS-approved unit list for HB 1379 compliance — Hoot, MicroFAST, Singulair, AdvanTex, Hydro-Action — with NSF 245 testing, performance bonds, and report cadence.

A Florida PE designing a residential onsite system for an HB 1379 BMAP parcel pulls from a list of roughly 14 currently-approved Performance-Based Treatment System units under 62-6.028 F.A.C. Five of those models account for ~90% of installs I've stamped between 2022 and 2026: Hoot HSU, MicroFAST, Singulair Green, AdvanTex AX-RT, and Hydro-Action AN-Series. The remaining nine are either niche capacity or recently approved with short field-data files.

This is the list as it actually moves through FDEP review and the trade-offs that drive selection on a typical residential design. Not a marketing comparison — the operational reality after thirty stamped projects.

Part of the FL HB 1379 BMAP Compliance Guide guide.

The Approval Framework

A PBTS unit gets onto the FDEP approved list under 62-6.028(2) by passing three gates:

• NSF/ANSI Standard 245 certification (the Wastewater Treatment Systems — Nitrogen Reduction standard) by an ANSI-accredited testing lab, typically NSF International or BNQ
• FDEP technical review of installation, maintenance, and monitoring protocols under 62-6.028(3)
• Manufacturer performance bond under 62-6.028(7) covering replacement cost if the unit fails to maintain the certified TN performance — typically $5,000–$10,000 per unit, held by FDEP for the warranty period

The performance bond is what keeps the list short. Several otherwise-competent units from out-of-state manufacturers haven't bonded into Florida; their NSF 245 certification is fine, but the bond requirement is a deal-breaker for thin-margin operators.

The Five Workhorses

Hoot HSU (Hoot Systems, Lake Charles, LA)

Submerged aerated reactor with internal denitrification zone. Single-pass design, no recirculation pump.

• Capacity range: 500–1,500 GPD (residential through small commercial)
• Certified TN performance: 6.8 mg/L average, 95th percentile 9.2 mg/L (NSF 245 test data)
• Installed cost (residential 600 GPD): $9,500–$12,500
• Annual O&M cost: $480–$720 (linear-diaphragm aerator + quarterly contractor visits)
• Strengths: Simplest install, fewest moving parts, longest field-data history in Florida (Wakulla deployments back to 2011)
• Weaknesses: TN performance flattens around 6–7 mg/L — won't reliably hit IRL's 3 mg/L target without a polishing stage

MicroFAST (Bio-Microbics, Lenexa, KS)

Fixed-film aerobic treatment with internal media. Pre-engineered drop-in unit.

• Capacity range: 500–9,000 GPD (residential, commercial, and small community)
• Certified TN performance: 7.4 mg/L average, 95th percentile 11.2 mg/L
• Installed cost (residential 0.5 MicroFAST): $10,500–$13,500
• Annual O&M cost: $520–$780
• Strengths: Robust against intermittent loading (good for vacation homes), no media replacement for 12+ years
• Weaknesses: Higher headspace requirement (drop-in tank is taller); often forces a riser-extension on existing tank pits

Singulair Green (Norweco, Norwalk, OH)

Aerobic + anoxic stage with recirculation. Modular configuration.

• Capacity range: 500–1,500 GPD residential, plus larger commercial
• Certified TN performance: 5.9 mg/L average, 95th percentile 8.4 mg/L
• Installed cost (residential 600 GPD): $9,000–$12,000
• Annual O&M cost: $560–$820
• Strengths: Tighter TN performance than Hoot, broad Florida contractor base, parts availability is the best of the five
• Weaknesses: Recirculation pump is a maintenance item — replacement at year 6–9 runs $385–$550

AdvanTex AX-RT (Orenco Systems, Sutherlin, OR)

Recirculating textile media filter with TeleMetro telemetry option.

• Capacity range: 500–1,500 GPD residential; AX-100 series for larger commercial
• Certified TN performance: 4.2 mg/L average, 95th percentile 6.8 mg/L
• Installed cost (residential AX-20): $11,500–$15,500
• Annual O&M cost: $620–$950 (textile media replacement is the long-cycle wear item)
• Strengths: Best TN performance on the list — only PBTS that reliably hits the IRL 3 mg/L target without a polishing stage
• Weaknesses: Most expensive, most complex install, most demanding O&M cadence; textile media replacement at year 8–10 runs $1,200–$1,800

Hydro-Action AN-Series (Hydro-Action Industries, Beaumont, TX)

Aerobic + anoxic with pre-anoxic recirculation. Compact footprint.

• Capacity range: 500–1,500 GPD residential
• Certified TN performance: 6.5 mg/L average, 95th percentile 9.0 mg/L
• Installed cost (residential AN-500): $9,000–$11,500
• Annual O&M cost: $480–$700
• Strengths: Smallest footprint of the five (good for tight Eastpoint and St. George Island lots), competitive cost
• Weaknesses: Florida field-data history is shorter than the other four; Wakulla and IRL inspectors occasionally request supplemental sampling early in service life

The Selection Logic I Actually Use

For a typical Florida BMAP design, the unit choice falls out of three questions:

1. What's the TN target at the parcel?

• 3 mg/L (IRL): AdvanTex AX-RT is the default; nothing else reliably hits it without polishing
• 5 mg/L (Silver Springs PFA): Singulair Green or AdvanTex AX-RT
• 8 mg/L (Caloosahatchee): Hoot, MicroFAST, Singulair, Hydro-Action all qualify; pick on cost and contractor availability
• 10 mg/L (Wekiva, Apalachicola, most BMAPs): all five qualify

2. What's the parcel's loading pattern?

• Steady residential: any of the five
• Vacation/seasonal: MicroFAST handles intermittent best
• Commercial / heavy peak: Hoot or AdvanTex with upsized capacity

3. What's the contractor pool look like in the county?

• Brevard, Volusia: all five available, Singulair contractor base is largest
• Franklin, Wakulla: Hoot has the deepest contractor roster
• Orange, Seminole, Lake (Wekiva): Singulair and AdvanTex dominate
• Lee, Collier: AdvanTex and Hoot share the market

What FDEP Actually Reads on the Annual Report

The 62-6.030(7) annual operating-permit report that the inspector signs requires the following data points per unit type. The lab line is the binding number — if effluent TN exceeds the certified threshold by more than 20%, FDEP issues a non-compliance letter and the manufacturer's bond may be triggered.

• TN concentration (mg/L)
• BOD5 and TSS (mg/L)
• Aerator/compressor runtime hours
• Recirculation pump runtime hours (where applicable)
• Filter/media condition (where applicable)
• Pump-out volume (if performed)

What You Should Never Specify

Do not specify a PBTS unit that hasn't been installed in the specific BMAP basin before. The Wekiva Study Area basin-eligibility list is narrower than the statewide HB 1379 list; the Apalachicola Bay BMAP enforces a similar basin-track-record overlay informally. I've watched a stamped design come back from DOH-Seminole because the specified unit was statewide-approved but lacked Wekiva-basin field data. Pull the unit's basin-specific install count before you stamp.

Frequently asked questions

What's the short answer to "FDEP-Approved Nitrogen-Reducing Septic Systems: The 2026 PBTS List Designers Use"?

The FDEP PBTS-approved unit list for HB 1379 compliance — Hoot, MicroFAST, Singulair, AdvanTex, Hydro-Action — with NSF 245 testing, performance bonds, and report cadence.

Who does this apply to?

NEIWPCC-certified Title 5 system inspectors in Massachusetts, FDEP-licensed septic contractors in Florida, SCDHS-permitted designers in Suffolk County NY, and the property owners these professionals serve.

Where can I read the underlying regulation?

Every Complos guide links to the source statute or rule in the body. MA Title 5: 310 CMR 15.000. FL HB 1379 / HB 1417. NY: Suffolk County Sanitary Code Article 19. Always confirm with mass.gov / flsenate.gov / suffolkcountyny.gov before acting.

How does Complos help with this?

Complos generates the regulator's exact PDF, validates the inspection against the local overlay, and tracks per-town submission methods so you don't ship the report into a black hole. Start a 14-day trial at complos.ai/signup.

How Complos helps

Complos pulls the FDEP-approved PBTS list filtered to your BMAP basin's TN target, contractor pool, and unit field-data threshold — so you stamp a design that won't bounce at DOH review. Run the FL BMAP zone checker for the parcel's specific TN target, then pull installed-cost ranges by manufacturer and county.

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