Why SCDHS Rejects 12% of Article 19 Designs: The 5 I/A OWTS Errors That Trip Suffolk County Designers

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

TL;DR. SCDHS first-review rejection rate runs ~12% on Article 19 I/A OWTS designs. The five recurring errors — surface-water setback, hydraulic loading, sample port, PE seal, O&M proof — and how Suffolk designers pre-flight.

The Suffolk County Department of Health Services Office of Wastewater Management runs about 1,400 Article 19 I/A OWTS design submissions through first review every year. Internal SCDHS data shared at the Long Island Water Conference puts first-review rejection at roughly 12 percent. That number is not a quality-of-engineering complaint — most submitting designers are licensed PEs who pass on the second pass. It is a checklist failure rate.

Twelve percent is two weeks of revision time per project, and it concentrates in five errors. If you're submitting under §760-1607 and you've been rejected before, the cause is almost certainly on this list.

Part of the NY/Suffolk I/A OWTS Guide guide.

1. Surface-Water Setback Measured Wrong

The Article 19 §760-1607 setback to surface waters is 150 feet from the nearest point of the SAS to the mean high-water line of any tidal water body, perennial stream, or pond. The errors I see at first review:

• The designer measured to the bank rather than the mean high-water line, and the SCDHS reviewer pulled the NYS DEC Tidal Wetlands Inventory map and got a different number.
• The designer used the property survey's "edge of water" call, which on East End parcels can be 8–14 feet inland of the actual MHW line on a spring tide.
• The setback was measured to the SAS center rather than the nearest point of the SAS footprint, including any pressurized lateral.

The fix is to pull the DEC tidal-wetlands map (or the perennial-stream classification under 6 NYCRR Part 608 if it's freshwater) and measure to the regulator's line, not the surveyor's. SCDHS reviewers will check.

2. Hydraulic Loading Rate Misapplied to the Soil Texture

SCDHS publishes the I/A OWTS Standards table that maps USDA soil textural classes to allowable hydraulic loading rates. The error pattern:

• Designer pulls a perc test result of, say, 4 minutes per inch and assumes "fast soil, max loading."
• USDA textural class from the soil log is sandy loam, not loamy sand. The allowable loading rate drops accordingly.
• The SAS is sized off the perc rate alone, the textural class is wrong, and the SCDHS soil scientist on review re-classes the log and recalculates.

Perc rate alone does not size an Article 19 SAS. The sizing is hydraulic loading rate from the textural class, and the textural class comes from the soil log description, not the perc number. Designers who carried the conventional-system shortcut into I/A submissions get rejected for it.

3. Sample Port Specification Missing or Non-Compliant

Every Article 19 I/A OWTS unit requires an effluent sample port between the treatment unit and the SAS, accessible at grade, sized so a SCDHS-listed Operation & Maintenance contractor can pull a representative sample for the quarterly reporting required under §760-1608. The recurring failures:

• The detail shows a sample point inside the treatment tank rather than downstream of it.
• The port lid is flush concrete with no riser, so the O&M contractor would have to chip the cover off every quarter.
• The port is shown but the construction notes don't reference it, so it isn't in the contractor's bid and it doesn't get installed.

The reviewer can spot this in 30 seconds. Put the sample port on the plan, on the section, and in the construction notes, with a riser to grade and a screw-on or hinged lid.

4. PE Seal Placed Wrong or Sheet Set Incomplete

Article 19 designs must be sealed by a New York State licensed Professional Engineer. The seal failures:

• Sheet 1 sealed, sheets 2–4 unsealed. SCDHS requires every plan sheet that bears engineering content to be sealed and signed.
• Digital seal pasted as an image rather than applied per NYS Education Department §29.3 rules. The reviewer can tell, and an unverifiable seal kicks the package back.
• PE is licensed in another state but not in NY. Reciprocity is not automatic for Article 19 work; the engineer needs an active NY license number on the seal.
• The designer-of-record is the firm rather than an individual licensed PE. SCDHS wants the individual.

If you haven't filed under §760-1609(c) as a designer-of-record with SCDHS Office of Wastewater Management, do that before your next submission. The registration is one form and a copy of your active NY license; it short-circuits half the seal-related questions.

5. Operation and Maintenance Contract Proof Missing

§760-1608 requires the owner to enter into a maintenance contract with a SCDHS-listed O&M provider before the operating permit issues. Designers commonly leave the proof out of the design package because they think it's the owner's homework. SCDHS does not.

• A signed O&M agreement, or at minimum a letter of intent from the listed provider, must be in the submission package.
• The provider has to be on the current SCDHS-listed contractor roster — the list is published quarterly and contractors fall off it for missing reporting deadlines.
• The contract must reference quarterly sample collection and total-nitrogen reporting per §760-1608(d).

A design that's perfect on every other axis still gets rejected with "submit O&M agreement and resubmit" if this single document is missing.

What Pre-Flight Looks Like Before You Submit

Before any Article 19 package leaves my office, I run a 20-minute pre-flight against the five errors above:

• Pull the DEC tidal-wetlands or 6 NYCRR Part 608 stream classification map; measure to the regulator's line.
• Verify the soil log textural class against the USDA triangle; recalculate the hydraulic loading from the table, not from the perc rate.
• Confirm the sample port is on plan + section + notes with a riser to grade.
• Confirm every plan sheet has the active NY PE seal and signature.
• Confirm the O&M letter of intent or signed contract is in the package.

That sequence drops first-review rejections from 12 percent to under 3 percent in our office. The work isn't designing better — it's checking the same five things every time.

What Designers Should Never Do

Don't submit an Article 19 design without confirming the priority-watershed status of the parcel. If the parcel is inside one of the priority watersheds, the submission package needs the SoLR grant eligibility documentation attached so the homeowner's funding is queued in parallel with the construction permit. Designers who submit "just the design" force the homeowner to start grant paperwork from zero after permit issuance, which adds 8–14 weeks before any shovel moves.

Frequently asked questions

What's the short answer to "Why SCDHS Rejects 12% of Article 19 Designs: The 5 I/A OWTS Errors That Trip Suffolk County Designers"?

SCDHS first-review rejection rate runs ~12% on Article 19 I/A OWTS designs. The five recurring errors — surface-water setback, hydraulic loading, sample port, PE seal, O&M proof — and how Suffolk designers pre-flight.

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's pre-submission check overlays each Article 19 package against the SCDHS first-review checklist — surface-water setback, hydraulic loading, sample port, PE seal, O&M proof — and flags the five common rejections before the package leaves your office. Run the SCDHS grant eligibility check alongside to bundle the homeowner's funding paperwork with the design submission.

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