RV Park Septic and Water Rules by State: Texas, Oregon, and Washington

Why Buyers and Lenders Ask About Septic and Water First

Septic and water decide how many sites a park can legally run. If your permit supports fewer sites than you rent, a buyer may only value the sites the permit supports. If you have crossed a state threshold without the right permit, the buyer is pricing a future engineering project. And if a private well serves the public, there may be testing and reporting rules the buyer has to inherit.

None of that kills a sale. Not knowing your numbers is what costs you.

Texas: The 5,000 Gallons-Per-Day Line

Texas septic systems are "on-site sewage facilities" (OSSFs), regulated by the Texas Commission on Environmental Quality (TCEQ) under Title 30, Texas Administrative Code, Chapter 285.

The rule that matters most for RV parks: 30 TAC 285.3(g)(1). Under "Exclusions," the OSSF rules say:

"The following systems are not authorized by this subchapter and may require a permit under Chapter 205 or Chapter 305 of this title (relating to General Permits for Waste Discharges or Consolidated Permits, respectively): (1) one or more systems that cumulatively treat and dispose of more than 5,000 gallons of sewage per day on one piece of property;"

Source: 30 TAC 285.3, current text, matching TCEQ's OSSF rules compilation, RG-472.

In plain English: once the systems on one property add up to more than 5,000 gallons of sewage a day, the OSSF program no longer covers them. You may need a TCEQ wastewater permit instead. TCEQ says facilities that dispose of treated effluent by land application (surface irrigation, evaporation, drainfields, or subsurface land application) need a Texas Land Application Permit (TLAP), and facilities that discharge into water in the state need a TPDES permit (TCEQ domestic wastewater permits).

The same 5,000 number shows up in the OSSF definitions (30 TAC 285.2, in RG-472):

• A "recreational vehicle park" is a tract with rental spaces for two or more recreational vehicles that "has a combined wastewater flow of less than 5,000 gallons per day."
• An "on-site sewage disposal system" is one or more systems that "do not treat or dispose of more than 5,000 gallons of sewage each day."

Other Texas rules a seller should know:

• Permit required. A person needs a permit and approved plan to "construct, alter, repair, extend, or operate" an OSSF unless an exception applies (30 TAC 285.3(a)).
• Permits transfer on sale. OSSF permits "shall be transferred to a new owner automatically upon sale or other legal transfer" (30 TAC 285.3(a)(3)).
• Hooking up RVs is not construction. "Connecting recreational vehicles or manufactured homes to rental spaces is not considered construction if the existing OSSF system is not altered" (30 TAC 285.3(f)(3)).
• Manufactured housing communities. If you also rent spaces to manufactured homes on an OSSF, 30 TAC 285.4(a)(2) requires a sewage disposal plan prepared by a professional engineer or professional sanitarian, and says total anticipated flow for the tract "shall not exceed 5,000 gallons per day."
• Local rules can be stricter. TCEQ says "TCEQ is not often the OSSF permitting authority" and "Local permitting programs can be more stringent than State minimums" (TCEQ OSSF permits).

What to pull in Texas: your OSSF permit, the notice of approval, the planning materials that show design flow, pump and repair records, and any TCEQ wastewater permit if you are over 5,000 gallons per day. Confirm everything with your county or city permitting authority or your TCEQ regional office. More on selling in Texas: Texas RV park sale.

Oregon: The 2,500 Gallons-Per-Day WPCF Line

Oregon's onsite rules are OAR Chapter 340, Division 71, run by the Department of Environmental Quality (DEQ).

• WPCF permit above 2,500 gpd. Under OAR 340-071-0130(15)(b)(A), any system or combination of systems on the same property or serving the same facility with "a total sewage flow design capacity greater than 2,500 gpd" must be built and operated under a renewable Water Pollution Control Facilities (WPCF) permit.
• Existing systems. Under OAR 340-071-0130(16)(a), an existing system that would need a WPCF permit doesn't need one "until a system major repair or major alteration of a system, or facility expansion, is necessary."
• Large systems. OAR 340-071-0100(89) defines a "Large System" as one "with a projected daily sewage flow greater than 2,500 gallons." DEQ says large systems have extra requirements under OAR 340-071-0520, including a groundwater assessment (DEQ fact sheet).
• Permit terms. DEQ says local construction permits are valid for up to one year, while WPCF operating permits are issued for up to 10 years and renewed for the life of the system.

More on selling in Oregon: Oregon RV park sale.

Washington: The 3,500 Gallons-Per-Day LOSS Line

Washington sorts septic jurisdiction by design flow (DOH regulatory jurisdiction):

• 0 to 3,499 gpd: the local health officer
• 3,500 to 100,000 gpd: the Department of Health Large On-site Sewage System (LOSS) Program
• Over 100,000 gpd: the Department of Ecology

DOH lists "campgrounds and recreation vehicle parks" among typical LOSS users (DOH LOSS program). Under WAC 246-272B-01300, LOSS owners "shall obtain an operating permit from the department and shall renew it annually." Older permitted LOSS that don't fully meet the current rule "may continue in service without upgrade until modified, expanded, or repaired."

More on selling in Washington: Washington RV park sale.

The Federal Layer: EPA Large-Capacity Septic Systems

On top of state rules, the U.S. EPA treats some septic systems as Class V injection wells under its Underground Injection Control (UIC) program. According to the EPA, a septic system is a "large capacity septic system" if it "receives solely sanitary waste either from multiple dwellings or from a non-residential establishment and the system has the capacity to serve 20 or more persons per day." EPA lists "Recreation or vehicle (RV) parks" and "State parks and campgrounds" among the facilities where these systems are found.

EPA also says states and tribes can run the UIC program and "can always adopt more stringent requirements," and that EPA does not regulate single-family septic systems or non-residential systems that serve fewer than 20 persons per day. Once a large-capacity system takes anything other than sanitary waste, EPA says it is no longer a large-capacity septic system. Industrial waste, for example, makes it an industrial waste disposal well. Keep chemical and shop waste out of your system.

Water: When a Well Becomes a Public Water System

Federal baseline: the EPA says a public water system "provides water for human consumption through pipes or other constructed conveyances to at least 15 service connections or serves an average of at least 25 people for at least 60 days a year." EPA names campgrounds as an example of a transient non-community water system (EPA).

States carry it out, and their lines differ:

• Texas: a public water system "must have at least 15 service connections or serve at least 25 individuals at least 60 days out of the year" (30 TAC 290.38).
• Oregon: the line is lower. It covers piped systems with "more than three service connections," or a public or commercial establishment open at least 60 days a year and "used by 10 or more individuals per day" (OAR 333-061-0020).
• Washington: Group A systems meet the federal definition. A transient noncommunity Group A system serves, among other cases, "twenty-five or more different people each day for sixty or more days within a calendar year." Group B systems are public systems that don't meet Group A (WAC 246-290-020).

Every state counts connections and people its own way. Call your state drinking water program and ask how your park is classified.

The Documents to Bring

The septic permit is one of the four documents we ask for first. Bring what you have:

1. Septic permit(s) and the notice of approval or final inspection
2. Design flow or planning materials
3. Any state operating permit (Texas TCEQ wastewater permit, Oregon WPCF, Washington LOSS)
4. Pump, repair, and monitoring records
5. Water system ID, classification, and sample history if you have a well

See the documents-first fast track for the full set, and our wild cards page for permit and zoning surprises.

Confirm With Your State

Rules change, local offices can be stricter, and how your flow is calculated depends on your park. Before you rely on any number on this page, confirm it with:

• Texas: your county or city OSSF permitting authority, or your TCEQ regional office
• Oregon: your county onsite program or DEQ, and the Oregon Health Authority for water
• Washington: your local health jurisdiction or DOH's LOSS program, and DOH for water

Not legal or engineering advice. This page summarizes public rules for general education. A licensed engineer, sanitarian, or onsite designer and your permitting authority make the real calls on your system.