Septic in Pawhuska, OK

In Pawhuska, you'll notice plenty of homes tucked on generous yards where the yardwork and drainage patterns tell a story before you ever step inside. I'm a local septic contractor who lives and works here too, so I know the rhythms of Pawhuska life—the quick summer storms, the way soil breathes after rain, and the practical realities of keeping a household running smoothly. Think of this as practical, neighbor-to-neighbor guidance you can trust.

Is septic common in Pawhuska? Should I expect septic if I own or buy a home?

Yes—especially if your home sits outside the city sewer boundaries or was built before a municipal sewer line reached the street. Many newer—or recently upgraded—rural and semi-rural properties rely on septic systems to manage wastewater. If a home is in town and connected to city sewer, you'll see different plumbing expectations. When you're buying, it's wise to confirm whether the property uses a septic system, and if so, request the current operating permit, the pump history, and any inspection records. A clean, documented septic history is a strong signal you're making a solid, informed choice.

Why homes typically use septic systems in Pawhuska

• Rural layout and infrastructure: Pawhuska's charm includes lots with room to spread out, where extending a city sewer line to every property isn't practical or economical.
• Soil and groundwater considerations: Our soils and drainage patterns work well with conventional septic designs when properly sized and installed, helping protect wells and surface water.
• Cost and practicality: For many homeowners, a well-maintained septic system is a cost-effective, long-term solution for wastewater treatment when municipal options aren't available.

High-level explanation: why septic exists here

A septic system is a simple, hardworking solution that uses a tank and a drain field to separate solids from liquids, followed by natural soil processes that treat the effluent before it returns to the ground. In Pawhuska, the regular cycles of rain, drought, and farming activity mean a well-designed system, properly installed and periodically serviced, does the heavy lifting of protecting your family and property. Regular maintenance—like timely pumping and mindful waste disposal—keeps the system healthy and your yard free from backups or odors, which is exactly what practical, reliable home ownership looks like here.

If you're navigating this for a current or prospective Pawhuska home, you'll find practical, neighborly guidance already waiting to help you keep your septic system in good shape.

Where Septic Systems Are Common in Pawhuska

Rural and unserved areas

• In Pawhuska, septic systems are most common on rural properties outside the city sewer service boundaries.
• Farms, ranches, and country homes on acre-plus lots typically rely on a septic system to treat waste on-site.
• Developments or properties established before sewer lines were extended often use septic when municipal sewer isn't available.

Inside-town considerations

• Within the broader Pawhuska area, some properties still operate on private systems where public sewer is not connected to the home or lot. If you're unsure whether your address has sewer service, verify with local utility providers or the county health authority.
• When buying in or near town, always confirm current sewer availability and any local ordinances that affect septic use or replacement.

Soil, slope, and drainage factors

• Soil percolation rate and depth to groundwater are the biggest drivers of septic suitability.
• Well-drained soils (such as some loams) support typical drainfields, while heavy clays, shallow bedrock, or compacted soils may require specialized designs.
• Areas near streams, floodplains, or perched water tables demand professional evaluation to prevent system failures.

Common system designs you'll see here

• Conventional gravity septic tanks with soil absorption fields for standard lots.
• Mound systems or sand filters on properties with limited suitable native soil or high water tables.
• Alternative designs on smaller lots or challenging sites, installed by licensed septic professionals.

How to tell if your Pawhuska property uses septic (and what to do)

1. Check your address with local sewer maps or the county health department to see if a sewer connection exists.
2. Look for a septic tank access lid, a buried tank, or a drainfield on the property plan or site diagram.
3. If you're buying, request any existing septic permits, maintenance records, or inspection reports from the seller.
4. Hire a licensed septic installer or a soil testing professional to evaluate percolation, tank condition, effluent lines, and seasonal water table.

Resources to help you

• Oklahoma Department of Environmental Quality (DEQ) – Onsite Wastewater Systems: https://www.deq.ok.gov/
• Oklahoma State University Extension – Onsite Wastewater Information: https://extension.okstate.edu/

Quick reference: typical lot and home setups in Pawhuska

• Common home size: single-family homes on rural lots of roughly 1–5 acres.
• Typical septic: one septic tank with a designated drainfield, sized for household usage.
• When planning: start with soil and site evaluation, then choose a design that meets local health and building codes.

Septic vs Sewer: What Homeowners in Pawhuska Should Know

What septic vs sewer means for Pawhuska

• Pawhuska sits in Osage County, where not every property automatically ties into a municipal sewer system. Some homes are on city sewer, while others rely on on-site septic systems. The key question is: is a sewer connection available where you live, and is it practical or affordable to connect?
• If you don't have access to a sewer line, a properly designed and maintained septic system on your property is a reliable, cost-effective alternative. If sewer service is available, you'll need to weigh installation, connection fees, and ongoing monthly bills against septic ownership.

How the systems work in practice

• Septic system (on-site): Wastewater flows from your home into a septic tank underground, where solids settle and fats/oils float. Liquid effluent then drains to a designated drain field. You're responsible for system design, maintenance, and pumping.
• Municipal sewer: All household wastewater is carried through a network of pipes to a centralized treatment facility operated by the city or county. You pay a recurring sewer bill, and maintenance is handled by the utility.

Pros and cons at a glance

• Septic pros: independence from monthly sewer bills, long-term potential cost savings, stands alone on rural or unserved parcels.
• Septic cons: routine maintenance is essential; failure or improper use can cause costly repairs; siting, installation, and pumping require professional oversight.
• Sewer pros: no on-site pumping or drain-field maintenance, predictable monthly costs, centralized treatment.
• Sewer cons: utility bills can rise; you rely on the reliability of the municipal system; some homes may face costly or disruptive connection projects.

When to consider sewer connection

• If you have an accessible, affordable connection to a public sewer line and your local authority encourages or requires connection, it may be worth evaluating.
• Factors to compare:
  • Upfront connection/impact fees versus septic system replacement or major repairs.
  • Ongoing monthly sewer charges versus annual septic pumping and maintenance costs.
  • Property value, home expansion plans, and soil/lot suitability for septic drain fields.

Step-by-step: evaluating a sewer connection in Pawhuska

1. Confirm availability: Contact the City of Pawhuska utilities or Osage County/County Health Department to determine if sewer service is available for your address.
2. Get a cost estimate: Ask about connection fees, any required upgrades, and monthly rates.
3. Assess timelines: If a tie-in requires trenching or street work, understand the schedule and disruption.
4. Compare with septic: Have a contractor estimate replacing or upgrading your septic system if you stay on-site, including pumping, repairs, or installation of a new system.
5. Decide and proceed: Choose the option that best fits your budget, timeline, and long-term plans, then follow permitted steps to complete the project.

Maintenance basics you should know

• Regular pumping: most septic tanks require pumping every 3–5 years, depending on household size, tank size, and water usage.
• Protect the drain field: avoid driving over the area, plant deep-rooted trees nearby, and limit irrigation over the field.
• Mind the inputs: minimize flushable wipes, fats/oils, solvents, pesticides, and non-biodegradable materials entering the system.
• Use water wisely: fix leaks, spread laundry loads, and stagger heavy water use to prevent overload.

Signs your septic needs attention

• Slow drains, gurgling sounds, or frequent backups
• Strong, unusual odors near the septic tank or drain field
• Wet, spongy, or unusually lush areas in the septic drain field area
• Standing water or saturated soil after rainfall

Official resources

• EPA: Septic Systems overview and consumer guidance.

Typical Septic System Types in Pawhuska

Conventional septic systems

• How it works: A buried septic tank collects wastewater, separates solids, and allows clarified effluent to drain by gravity or pressure into a subsurface drainfield where soil microbes finish the treatment.
• When it fits: Most rural Pawhuska homes with decent soil permeability and enough space.
• Pros: Simple design, broad availability of parts and contractors, typically the lowest upfront cost.
• Cons: Relies on good soil conditions; high groundwater, clay, or bedrock can cripple drainage and require a bigger drainfield or an alternative system.
• Practical tip: A local septic contractor can perform a site evaluation and estimate drainfield size based on lot size, usage, and soil.

Sand mound systems

• When used: Very shallow to marginal soils, high water tables, or where the native soil won't drain adequately.
• How it works: An elevated drainfield built on a mound of imported sand, with a distribution network above the natural soil.
• Pros: Enables septic treatment where conventional systems won't work; accommodates limited space vertically.
• Cons: Higher installation and maintenance costs; larger above-ground footprint and more components to monitor.
• Practical tip: Not every property qualifies; your contractor will verify site conditions and state/local permit requirements.

Chamber or grid drainfield systems

• How it works: Instead of conventional trenches, modular plastic chambers or grids create a longer, open soil infiltration area with flexible trench layouts.
• Pros: Easier to install in uneven terrain or narrow lots; can reduce trench width and backfill effort.
• Cons: Higher upfront cost than a traditional drainfield; performance still depends on soil and groundwater conditions.
• Practical tip: Works well when space is limited but soil still has adequate percolation.

Aerobic Treatment Units (ATUs)

• How it works: A mechanical aeration unit treats wastewater to a higher quality before it enters the drainfield.
• Pros: Suitable for marginal soils or tighter lots; can allow a smaller drainfield or alternate discharge options.
• Cons: Requires electricity, regular professional service, and routine maintenance; higher ongoing costs.
• Practical tip: In Pawhuska, ATUs are commonly paired with smaller or alternative drainfields to meet local site constraints. Check local permit requirements before installing.

Drip irrigation and evapotranspiration (ET) beds

• How it works: Treated effluent is distributed via subterranean drip lines or planted ET beds for disposal.
• Pros: Potential water reuse, efficient use of space, reduced surface signature.
• Cons: Design complexity and climate considerations; not suitable for every soil or landscape.
• Practical tip: Consider if you have a landscaping plan that can accommodate the system and local water rights or regulations.

Holding tanks and other temporary options

• How it works: Sealed tanks that hold wastewater when a full system isn't feasible or during a shutdown/transition.
• Pros: Flexible for seasonal use or during replacement.
• Cons: No treatment of effluent in storage; requires frequent pumping; often regulated as a temporary measure.
• Practical tip: Usually a stepping stone rather than a long-term solution; plan for a permanent system with permit compliance.

Local considerations in Pawhuska

• Soil variability (including caliche layers or variable percolation) and groundwater proximity influence system choice and size.
• Permitting and inspections are required by the Oklahoma DEQ and local health authorities; verify requirements before design or installation.

Official resources

• EPA: Septic Systems
  • https://www.epa.gov/septic
• Oklahoma DEQ (state regulations and guidance)
  • https://www.deq.ok.gov/
• Oklahoma State University Extension (homeowner guidance)
  • https://extension.okstate.edu/search.html?query=septic%20system

Common Septic Issues in Pawhuska

Signs of trouble to watch for

• Slow drains, frequent backups, or toilets that gurgle.
• Unusual sewage odors around the home or yard.
• Wet, boggy patches or lush, green spots over the drainfield area.
• Water pooled near the septic tank access lid or leach field.
• Sump pump or foundation drains tied into the septic system, causing overload.
• Excessive landscaping irrigation or heavy rainfall stressing a working system.

Why Pawhuska-specific factors matter

• Soil variations in Osage County: Some Pawhuska-area lots sit on clay-heavy soils with lower permeability, which slows effluent absorption and can lead to surface dampness or backups after normal use. This makes proper tank sizing, maintenance, and field loading especially important.
• Seasonal weather: Oklahoma's spring rains and rapid thaw cycles can saturate soil, reduce drainage, and push a system toward backup or surface seepage. Conversely, prolonged dry spells can cause cracking or shifting that disrupts the tank and pipes.
• Groundwater and flood risk: Certain Pawhuska properties have higher groundwater tables or flood-prone zones, which can raise the water table around the drainfield and hamper effluent dispersal.
• Tree roots and landscape: Rural or newer yard landscaping with aggressive roots (willow, cottonwood, pecan, maples) can intrude into septic lines and leach fields, especially when the system is old or undersized for current usage.

Common septic problems you'll see in Pawhuska

• Clogs and poor drainage
  • What happens: Kitchen grease, food scraps, and thick wipes (even "flushable" ones) clog pipes and baffles, slowing or stopping flow.
  • Why Pawhuska: Rural lots often have smaller trenches or older leach fields that are more quickly overwhelmed by organic buildup.
• Leach field failure
  • What happens: Ground becomes saturated near the drainfield; effluent may surface or odors appear beyond the tank.
  • Why Pawhuska: Clay soils and seasonal rains reduce infiltration capacity; repeated overuse or shallow beds accelerate failure.
• Tree roots invading lines
  • What happens: Roots wrap around pipes or push into joints, causing cracks or blockages.
  • Why Pawhuska: Mature yards with tall trees are common; roots actively seek moisture from the septic system.
• Aging components
  • What happens: Cracked tanks, corroded metal components, or deteriorated baffles fail to separate solids or direct flow.
  • Why Pawhuska: Many homes are older; original systems may not meet modern loading or setback expectations.
• Overuse and improper irrigation
  • What happens: Excessive water use from laundry, showers, and outdoor irrigation saturates the drainfield.
  • Why Pawhuska: Rural properties often rely on irrigation wells or seasonal watering that coincides with system loading.
• Inadequate maintenance
  • What happens: Septic tanks not pumped on a recommended cycle can accumulate solids, leading to backups and a stressed drainfield.
  • Why Pawhuska: Access to licensed professionals and knowledge of local maintenance intervals can vary by area.

Quick diagnostic and response steps

1. Note symptoms and time frame: Did backups start after a pump-down, heavy rains, or a new irrigation project?
2. Inspect visible signs: Look for odors, damp soils, or standing water near the tank lid or drainfield.
3. Restrict water usage temporarily: Avoid heavy loads (laundry, dishwashing) while you assess the system.
4. Schedule a licensed septic professional: Have a pro evaluate tank integrity, baffles, and drainfield condition; they can perform pumping, camera inspection, and field tests if needed.

Resources for Pawhuska homeowners

• EPA septic systems overview:
• Oklahoma Department of Environmental Quality (DEQ) homepage: https://www.deq.ok.gov/

Septic Inspection, Permits & Local Oversight

State and local roles in Oklahoma

• The Oklahoma Department of Environmental Quality (ODEQ) sets statewide standards for onsite wastewater systems and administers the state program for permit review and overall compliance.
• Local oversight is usually handled by the county health department (in Osage County this is your Osage County Health Department). They manage permits, perform site evaluations, approve system designs when required, and conduct inspections during installation and after completion.
• If your property sits inside the City of Pawhuska limits, in addition to county oversight you may encounter municipal permitting requirements. Always check with Pawhuska City Hall or the city Building/Code office to confirm whether a city permit is needed.

Do you need a permit?

• Yes, for most new septic systems, replacements, repairs that change the system, or any substantial modification.
• Permits cover design approval, installation, and final certification that the system meets state and local standards.
• Work begun without a permit can lead to fines, required removal or redesign, and delay when you sell the home.

How to apply in Pawhuska, Osage County

1. Hire a licensed septic installer and, if required, a licensed design professional.
2. Schedule a site evaluation and soil testing (perc test) as part of the planning process.
3. Prepare or obtain a system design that meets state and local requirements.
4. Submit a permit application package to the Osage County Health Department (or the applicable local office) with:
   • Property description and legal parcel information
   • Soil tests and site evaluation results
   • System design plans and any supporting calculations
   • Contractor and designer licenses
   • Permit fee payment
5. Wait for review and approval. If changes are needed, address them promptly and resubmit.
6. Once approved, proceed with installation under required inspections.

Inspections you should expect

• Most jurisdictions require inspections at key milestones:
  • After excavation or trenching begins and before backfilling
  • When the septic tank, distribution box, and pump/controls are installed
  • When fill is completed and the system is tested
  • Final inspection and certification of completion
• Have your as-built drawings, system labels, and maintenance instructions ready for inspectors.

Maintaining records after installation

• Keep all permit documents, inspection reports, and the final as-built plan in a safe place.
• Maintain a maintenance log for pumpouts, inspections, and any repairs.
• When selling, provide the buyer with the permit record and service history to reassure buyers and satisfy lender requests.

Quick tips and common pitfalls

• Do not start construction before obtaining the required permit from the Osage County Health Department or the local authority.
• Ensure all work is performed by licensed professionals and that installers submit inspection requests in a timely manner.
• If soil conditions are challenging, discuss alternative designs (e.g., mound systems) early in the planning process.
• Verify setback requirements (distance from wells, streams, property lines) with the inspector to avoid redesigns.
• Keep an organized file of all correspondence, inspection reports, and final approvals.

Useful resources

• Oklahoma DEQ – Onsite Wastewater Program: https://www.deq.ok.gov/wastewater/onsite-wastewater/
• Osage County Health Department (local permitting and inspections): contact local county health office for the current permit process and fees. Check the official Osage County website for the health department page.
• City of Pawhuska (municipal permitting inquiries): contact Pawhuska City Hall or the Building Permits office to confirm any city-specific requirements.

Septic Maintenance for Homes in Pawhuska

Pawhuska-specific soil and climate influences

Osage County soils can be variable, with areas of heavier clay and seasonal moisture swings. Pawhuska's springs can be wet, while hot summers and occasional heavy rain can create saturated conditions around the drainfield. Freeze-thaw cycles also affect soil structure, which can impact infiltration and distribution in the leach field. Have a local septic pro evaluate whether your drainfield needs seasonal adjustments (e.g., drainage management, plantings that minimize root intrusion, or alternative designs) based on the soil and slope on your property.

Regular inspections you can trust

• Schedule a licensed septic system inspection once a year, plus a pumping assessment every 3–5 years (depending on tank size and household usage).
• A technician will check: tank integrity, baffles, sludge and scum layers, effluent filters, pump if you have an ATU or pump chamber, and the condition of the drainfield lines and soil absorption area.
• Homeowner checks you can do: listen for gurgling drains, note slow drains, watch for sewer odors inside or outside, and look for damp, unusually lush spots or odorous patches over the drainfield.

Pumping and tank care in Pawhuska

• Typical family households in Pawhuska with standard tank sizes should plan to pump every 3–5 years. Frequency depends on tank size, number of occupants, and water-use habits.
• A key guideline: pump when solids (sludge and scum) occupy about one-third of the tank's capacity, or sooner if you've had notices from a licensed contractor.
• Use a licensed septic contractor for pumping and inspection; they'll dispose of waste properly and can spot issues you might miss.

Drainfield protection in Pawhuska

• Do not park or drive heavy equipment over the drainfield or its pipes; soil compaction reduces infiltration.
• Keep tree and shrub roots away from the drainfield to prevent damage to distribution lines.
• Limit irrigation water near the drainfield and avoid landscaping with high-water-use plants directly over it.
• Use septic-safe products and avoid flushing anything other than toilet paper and human waste. Avoid greases, solvents, paint thinners, feminine products, wipes labeled "flushable," or chemical cleaners that can disrupt soil microbes.

Maintenance steps: a practical 5-step plan

1. Schedule and keep a yearly septic inspection with a licensed pro; log findings and pumping dates.
2. Maintain a simple records notebook or digital log including tank size, last pump date, and any repairs.
3. Manage water use: fix leaks, spread laundry over several days, and consider high-efficiency fixtures to reduce load.
4. Monitor landscaping: plant trees and shrubs away from the drainfield; irrigate away from the absorption area.
5. Be cautious with additives: most systems don't require chemical additives; follow professional advice and avoid unproven products unless recommended.

Signs your Pawhuska septic needs attention

• Sewage odors around fixtures or outside near the drainfield.
• Slow drains, frequent backups, or toilets flushing unusually slowly.
• A soggy, spongy, or unusually green patch over the drainfield.
• Gurgling sounds in plumbing or standing water near the septic tank or leach field after heavy rainfall.

When to call a pro in Pawhuska

• If you notice persistent odors, backups, or wet areas over the drainfield, or if a routine inspection flags issues with baffles, pipes, or the absorption area.
• Sudden changes after a flood or significant rainfall may require field assessment and possible remediation.

Official resources:

• EPA: Septic Systems (onsite wastewater) basics and best practices: https://www.epa.gov/septic
• Oklahoma Department of Environmental Quality (Onsite Wastewater Systems information): https://www.deq.ok.gov/water-quality/onsite-wastewater-systems/

Cost Expectations for Septic Services in Pawhuska

Septic Tank Pumping

• What it includes: removing the sludge and scum from the tank, inspecting the inlet and outlet baffles, checking the tank's condition, and recording a recommended pumping frequency based on usage and tank size.
• Pawhuska specifics: many homes here use conventional tanks. Local soil and water table can affect how often pumping is advised; if you've noticed sluggish drains or odors, it's a sign to pump sooner.
• Typical cost in Pawhuska: roughly $300–$600, with larger tanks or remote locations pushing toward $600–$800. Additional disposal surcharges may apply.
• When to schedule: every 3–5 years for average households; more often if you have a garbage disposal, heavy use, or a smaller tank.

Routine System Inspections and Maintenance

• What it includes: visual inspection of the tank access, pump chamber (if present), filters (if installed), effluent screen, and the drainfield area; check for surface pooling or odors; may include a dye test or camera inspection for deeper issues.
• Pawhuska specifics: annual or every 2–3 years is common for older systems; in areas with clay-rich soils, more frequent checks can help catch problems early.
• Typical cost in Pawhuska: basic inspections around $100–$250; more thorough evaluations with camera work or dye testing typically $250–$450.
• When to schedule: after major renovations, before listing a home, or if you're selling to avoid last‑minute surprises.

Drain Field Evaluation and Repair

• What it includes: soil and drainage assessment, field loading test, moisture checks, and diagnosing effluent distribution; repair work may involve replacing failed trenches, installing distribution boxes, or adding gravel/remediation.
• Pawhuska specifics: repair costs rise with older drainfields and restricted access to repair zones; in some properties, larger or alternative drainfields are needed.
• Typical cost in Pawhuska: $2,000–$7,000 for repair; if a full replacement is needed, costs can range $7,000–$15,000 or more, depending on size and equipment.
• When to schedule: if notice of damp areas, gurgling sounds, or persistent odors appears despite pumping.

Perc Test/Soil Evaluation for New System

• What it includes: soil profile analysis, percolation testing, and a design recommendation for a conventional vs. alternative system.
• Pawhuska specifics: local regulations require a soil evaluation to determine the appropriate system type before installation.
• Typical cost in Pawhuska: $500–$1,500 for the evaluation and reporting; design and permitting may add further.
• When to schedule: early in home buying, land development, or when replacing a failing system.

New System Installation and Replacement

• What it includes: system design, permit acquisition, trench or mound installation, backfill, disposal site selection, and final startup tests.
• Pawhuska specifics: costs vary with soil type and method (conventional vs. mound or ATU) and may require special site work.
• Typical cost in Pawhuska: conventional systems usually $5,000–$12,000; high‑end or mound/advanced treatment units can run $15,000–$25,000+.
• When to schedule: for new homes without a septic or replacing a failing system.

Drain Field Jetting and Root Removal

• What it includes: hydro-jetting line segments to remove grease and mineral buildup, root cutting if roots intrude on lines, and follow‑up inspection.
• Pawhuska specifics: effective where trees or shrubs near the field are causing intrusion; may require trenching or reseeding after work.
• Typical cost in Pawhuska: $200–$600 depending on length and accessibility.

Grease Trap and Interceptor Pumping

• What it includes: pump-out, removal of accumulated fats and solids, and cleaning of the trap or interceptor; suitable for homes with separate grease management before discharge to the septic system.
• Pawhuska specifics: more common in properties with kitchens that generate higher grease loads.
• Typical cost in Pawhuska: $150–$500.

Alarm, Valve, and Access Port Maintenance

• What it includes: inspecting alarms, float switches, pump controls, venting, and access covers; replace worn components as needed.
• Pawhuska specifics: keeping these components functional helps prevent surprises in freezing winters and rainy seasons.
• Typical cost in Pawhuska: $150–$350 per service visit.

Emergency/After-Hours Service

• What it includes: rapid response for backups, odors, or overflow; diagnostic assessment and necessary pumping or repair.
• Pawhuska specifics: after-hours rates apply; scheduling may depend on the technician's availability.
• Typical cost in Pawhuska: call-out fee $100–$250 plus any required pumping or repair, often totaling $250–$600+.

Upgrades to Alternative Treatment Units (ATU) or Enhanced Systems

• What it includes: assessment, design, installation, and required permits for advanced treatment options when a conventional system isn't viable.
• Pawhuska specifics: ATU options can be more common where soil or space constraints exist.
• Typical cost in Pawhuska: $8,000–$30,000+ depending on unit type and site requirements.

Preparation steps for service (quick guide)

1. Schedule in advance and confirm access for service vehicles.
2. Clear the area around the tank lid and drainfield access points.
3. Limit water use 24 hours before a pumping or inspection to get accurate readings.

Official resources:

• EPA: Septic Systems - https://www.epa.gov/septic
• Oklahoma DEQ On-site Wastewater Systems (official): https://www.deq.ok.gov/waste-management/wastewater-on-site-systems/