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Septic on a lake lot: what to check before you buy

References checked Oct 4, 2026.

Short answer: If a lake home uses an on-lot septic system, Pennsylvania's Act 537 required a permit for it from a local agency, so start by asking that agency for the lot's permit records.¹ Then hire an inspector who follows a published inspection standard, because the state does not set a method for septic inspections.²

Act 537 in one paragraph

Act 537 is the Pennsylvania Sewage Facilities Act, enacted January 24, 1966.¹³ Under Section 7, no one may install, build, alter, repair or connect to an individual sewage system, or occupy a building that needs one, without first getting a permit showing that the site and plans meet the act's standards.¹ Permits are handled by a local agency, whose sewage enforcement officer (SEO) issues and reviews permit applications and does the inspections the act requires.¹ DEP's septic page tells homeowners to contact their local agency, normally the township's SEO, with questions.⁴

How a septic system works

DEP describes three main parts: the septic tank, a distribution box or dosing tank, and the absorption area.⁴ Solids settle in the tank as sludge, and the clearer liquid flows on to the absorption area, where it soaks through gravel and soil.⁴ DEP says tanks should be pumped at least every three to five years, depending on tank and household size, and that in Pennsylvania a three-bedroom home must have a tank of 900 gallons or more.⁴

Step 1: get the permit file

Ask the township's sewage enforcement officer for the records on the lot: the permit, the design, the final inspection and any repair permits. Compare what the records describe (bedrooms, system type, location) with the house you are buying. A house that grew from two bedrooms to four may have outgrown its system.

Step 2: read the contract language

Act 537 puts statements in some lot sale contracts. A contract for a lot with no community sewage system available must say so and say that a permit for an individual system will be needed; it must also tell the buyer to contact the local agency before signing.¹ A contract for a lot served by a holding tank must say so and give a history of the tank's yearly maintenance cost.¹ A system put in under the ten-acre permit exemption also needs a contract statement that soils and site testing were not done.¹

Step 3: hire an inspector who follows a standard

The Pennsylvania Septage Management Association (PSMA) says plainly: "In Pennsylvania there are no laws or regulations governing onlot wastewater treatment system inspections."² It adds that there is no government-set method for inspecting these systems.² PSMA trains and certifies onsite wastewater system inspectors who use the PSMA/NOF Inspection Standards, which cover tanks, distribution systems, pumps and absorption areas.⁵² PSMA suggests asking whether the inspector is PSMA-certified and current, and whether the inspection will follow the PSMA Standards.²

A regular home inspection is not a septic inspection. Pennsylvania's home inspection law says an examination limited to septic systems is not a "home inspection," and the law doesn't let a home inspector do work regulated by the Sewage Facilities Act without the right license.³

Step 4: ask about a hydraulic load test

A hydraulic load test (HLT) checks whether the absorption area can take the water the system is expected to handle on a peak-flow day. In PSMA's words, a known volume of clear liquid is put into the absorption area, the liquid level is recorded before and after, and the inspector returns the next day and repeats the process.⁶ PSMA's standards call for an HLT in listed situations, including a house vacant for more than seven days and intermittent vacation or seasonal use that the inspector finds atypical.⁶ That matters for a lake home that sits empty between visits. PSMA also notes that in Pennsylvania the expected peak flow is four hundred gallons for one to three bedrooms, plus one hundred gallons for each extra bedroom.⁶

What the seller must disclose

Pennsylvania's seller disclosure form must cover water and sewage systems or service.⁷ The seller only has to disclose known material defects and is not required to investigate.⁷ A clean disclosure is not a passing inspection.

Lake-specific questions

• Where exactly are the tank and absorption area, and how close are they to the lake?
• When was the tank last pumped? May I see the receipts?
• Was the system designed for the number of bedrooms the house has now?
• Has the house been used only seasonally? Will the inspector do a hydraulic load test?
• Does the township or the community require septic inspections or pumping on a schedule? (Ask; rules vary, and we don't list them.)

FAQ

Does Pennsylvania require a septic inspection when a house is sold?

PSMA says Pennsylvania has no laws or regulations governing on-lot system inspections.² Some local rules or lenders may require one; ask the township and your lender.

Who has the septic permit records?

The local agency that administers Act 537, usually through the township's sewage enforcement officer.¹⁴

Why would an inspector want to run water into the system?

That is a hydraulic load test. PSMA's standards call for one in some cases, such as a house that has been vacant more than seven days.⁶

How often should a tank be pumped?

DEP says at least every three to five years, depending on tank size and household size.⁴

The house will sit empty before closing. Does that matter?

Tell your septic inspector. PSMA's standards call for a hydraulic load test when a house has been vacant more than seven days.⁶ If there is time and the inspector agrees, the absorption area can instead be re-inspected after more than 30 days of continuous occupancy.⁶

Lakes where this comes up

• Arrowhead LakeMonroe County
• Gold Key LakePike County
• Harveys LakeLuzerne County
• Conneaut LakeCrawford County
• Deer LakeFayette County
• Indian Mountain LakeMonroe County