Septic in McDowell County, NC

Last updated: Mar 21, 2026

In McDowell County, you can hear the wind in the pines and see the Blue Ridge glow from the back porch—a place where homes sit on larger lots and backyards fade into wooded hills. For many families here, a private septic system is simply how wastewater gets treated and returned to the soil, especially outside town sewer corridors.

Is septic common in McDowell County? Yes. If you own or are buying a home in this part of western North Carolina, you should expect a septic system unless the property is directly connected to a municipal sewer line. When you're evaluating a home, ask for the septic permit, the design, and any pumping and maintenance records. A professional inspection can catch issues before they become surprises, and it helps you plan for the costs of upkeep, now and down the road.

Why homes typically use septic systems in McDowell County:

  • Rural and semi-rural layout: Many properties are spread out or tucked into hillside lots where extending a city sewer line isn't practical or affordable.
  • Cost and practicality: Connecting to a sewer system can be expensive and may require realignments of driveways or loss of usable land; a well-designed septic system fits the site and budget.
  • Soil and drainage realities: The soils here vary, and a properly designed septic system accounts for groundwater, slope, and seasonal moisture to protect wells and streams.
  • Local property standards: Septic systems are the standard solution for wastewater in numerous neighborhoods and older rural homes where city sewer service never reached.

County growth history and how that has impacted septic coverage:

  • Early growth and industry: McDowell County grew around small towns, forestry, and mining; most homes were built with individual wastewater solutions to serve single-family properties.
  • Postwar and suburban phases: As roads improved and more families settled around Marion and along key corridors, the need for dependable private systems remained, even as some areas began to see sewer expansion.
  • Modern development and aging infrastructure: Growth along highways brought newer subdivisions, but aging septic systems and hillside soils require careful maintenance and sometimes upgraded designs (mound, specialty drain fields) to stay compliant and safe.
  • Overall impact: The pattern of dispersed development means septic coverage is prevalent, with ongoing emphasis on proper installation, regular pumping, and timely repairs to keep groundwater and homes protected.

High-level explanation (why septic exists here): The combination of mountainous terrain, variable soils, and slower-infill growth means centralized sewer lines don't always reach every property. A well-planned septic system fits the landscape, keeps wastewater contained, and lets homeowners maintain comfort and value in McDowell County. If you're navigating a purchase or a upgrade, you're in good hands with a local, practical approach grounded in real-life Mountain County experience.

How Septic Is Regulated in McDowell County

Regulatory roles: state and county

  • In North Carolina, septic systems are regulated at the state level and enforced locally. The North Carolina Department of Environmental Quality (DEQ) runs the On-Site Wastewater Program, sets design standards, and issues permits for installation, repair, and replacement. Official resource:
  • McDowell County Health Department handles the on‑the-ground pieces: permit intake and plan review, inspections during installation, final approvals, and enforcement within McDowell County. Official resource:
  • For the rules that govern On-Site Wastewater Systems in North Carolina, see the state's On-Site Wastewater Manual and associated regulations. Official resources: On-Site Wastewater Manual (linked from DEQ), and state code references such as 15A NCAC 18A (On-Site Wastewater Systems).

Permits, design, and installation

  • A permit is required for new systems, repairs, or replacements. Do not start work until you have the permit.
  • System design must be prepared by a licensed On‑Site Wastewater System Designer and follow the North Carolina On‑Site Wastewater Manual.
  • The designer submits the plan to the McDowell County Health Department for review, and the state On‑Site Wastewater Program may also review the plan.
  • Once the plan is approved, a permit is issued. Work can begin only after you have the permit, and installations must be completed by a licensed installer.
  • Expect the process to consider soil conditions, setbacks from wells and buildings, and the appropriate system type (conventional, mound, drip, etc.) based on site constraints. For guidance, consult the state manual and your county health department.

Inspections and approvals during installation

  • Inspections occur at key milestones to verify compliance with the approved plan and state rules.
  • Typical inspection points:
    1. Before backfilling the trench or absorption area.
    2. During tank placement and piping setup.
    3. Final inspection and system commissioning.
  • Schedule inspections with the McDowell County Health Department as you reach each milestone. Final approval confirms the system is ready for use and aligns with regulatory standards.
  • If an inspection fails, follow the Health Department's guidance for corrections and re-inspection.

Maintenance and records

  • Homeowners are responsible for ongoing maintenance. Keep a file of all pumping and inspection records.
  • Regular pumping is typically recommended every 3–5 years, or per the pumper's and system designer's guidance, depending on usage and tank size.
  • Practice good habits to protect the system: minimize wastewater volume, avoid disposing of fats, oils, medications, harsh chemicals, and non-biodegradable items in the drain, and do not plant trees or install heavy structures over the drain field.
  • If you notice signs of trouble (gaps in cents, sewage odors, slow drains, wet areas over the drain field), contact the McDowell County Health Department promptly.

What to do if the system fails or needs repair

  • A system failure typically triggers a formal evaluation and may require a repair or replacement permit.
  • The Health Department will determine whether a repair, modification, or full replacement is needed and will require design and permitting consistent with state standards.
  • All work after a failure or repair must be performed under the appropriate permit and inspected to obtain final approval.

Official resources and where to look

Soil, Groundwater & Environmental Factors in McDowell County

Soils and septic suitability in McDowell County

Your septic system relies on soil to treat and disperse effluent. In McDowell County, you'll encounter a mix of rocky, shallow soils on ridges and deeper, loamy or clayey soils in valleys. Key soil factors to consider are texture and permeability, depth to bedrock or a limiting layer, drainage tendency, and the presence of restrictive layers (rock, hardpan, cemented pans) that limit effluent movement. Sloped sites can drain well, but steep terrain adds installation challenges and affects drainfield design.

  • Soil texture and permeability: very fast-draining sandy soils can shorten treatment time, while poorly draining clays can limit wastewater movement.
  • Depth to bedrock or hardpan: shallow rock or dense layers reduce usable drainfield depth.
  • Groundwater proximity: adequate separation between the drainfield and groundwater is essential for effective treatment; high seasonal water tables can reduce absorption.
  • Rocks and debris: stones, shale, or stony soils reduce usable drainfield area and raise placement costs.

What you can do

  • Get a soils evaluation from a licensed professional or the local health department per NC DEQ guidelines. This helps determine if a conventional drainfield, mound, or alternative design is appropriate. Official guidance: [NC DEQ Onsite Wastewater Program](
  • Request a percolation test or soil evaluation as part of site assessment, if required in your county, to confirm soil suitability before installation.
  • Use the findings to plan drainfield sizing, location, and future maintenance needs.

Groundwater depth, seasonal variations and water quality

Groundwater depth in McDowell County fluctuates with rainfall, topography, and bedrock fractures. Seasonal rains can raise the water table and reduce soil porosity around the drainfield, influencing how well effluent is treated and dispersed. Shallow groundwater or perched springs near the surface may limit where a system can be placed.

  • Look for wet or saturated soils after rain; these indicate limited absorption capacity in the near term.
  • Maintain appropriate setbacks from wells, streams, and property lines to protect drinking water sources and surface water.
  • Be mindful of groundwater quality; high nitrate or coliform indicators in nearby wells or springs warrant professional assessment.

Floodplains, wetlands & environmental protection

Siting near floodplains or wetlands requires extra care. Flooding can damage components and cause untreated effluent to back up or surface.

Site assessment steps (quick start)

  1. Hire a licensed professional or contact the McDowell County Health Department to conduct a soils evaluation and determine drainfield feasibility. Reference: NC DEQ guidelines.
  2. Review seasonal groundwater and bedrock depth using on-site observations and available maps.
  3. Check flood risk and setbacks via FEMA maps; identify any flood-prone zones on the property.
  4. Plan drainfield location with slope, drainage patterns, and proximity to wells and watercourses in mind.
  5. Obtain design approval from NC DEQ or the county before installation and follow up with annual maintenance checks.

Typical Septic System Types in McDowell County

Conventional gravity septic systems

  • What they are: A standard setup with a septic tank and a soil-based drainfield that uses gravity to move effluent from the tank into buried absorption lines.
  • Typical components: Septic tank, either a gravity trench or a bed in clean soil, and a distribution box to route effluent to the drain area.
  • Best-fit soils: Deep, well-drained soils with adequate room for the absorption area.
  • Pros:
    • Simple design, widely understood, and often less expensive upfront.
    • Easy to pump and service when maintenance is kept up.
  • Cons:
    • Requires sufficient soil depth and permeability; shallow or rocky soils, or high water tables, can be a problem.
    • Performance drops if the drainfield is overloaded or saturated.
  • Maintenance basics (steps you can follow):
    1. Schedule septic tank pumping every 3–5 years (even if you don't notice problems).
    2. Use water-saving fixtures and spread out laundry and high-flow activities.
    3. Protect the drainfield area from compaction and vehicles.

Chamber or gravel-less drainfields

  • What they are: Alternative trench systems using modular, porous chambers instead of traditional gravel trenches.
  • Why homeowners choose them: Often easier to install, lighter, and can require less backfill volume while providing good flow.
  • Pros:
    • Faster installation and flexible layout.
    • Comparable performance to conventional trenches when properly designed.
  • Cons:
    • Still requires adequate soil depth and proper dosing; damaged chambers can be costly to replace.
  • Maintenance basics:
    • Avoid heavy equipment on the drainfield and keep surface grading stable.
    • Regular inspections if paired with an ATU or other pretreatment.

Mound systems

  • When they're used: In areas with shallow soil, high water tables, or poor native soils where a conventional drainfield won't percolate properly.
  • How they work: A covered sand fill raises the drainfield above the natural grade; effluent is distributed through elevated lines into the mound.
  • Pros:
    • Expands usable locations and prevents surface pooling.
    • Can meet stricter state requirements in challenging sites.
  • Cons:
    • Higher upfront cost and more complex maintenance.
    • Surface vegetation and mowing require care to avoid soil compaction near the mound.
  • Maintenance basics:
    • Keep the mound free from heavy traffic, roots, and debris.
    • Monitor for surface dampness or odors and address promptly.

Aerobic Treatment Units (ATU) and advanced pretreatment

  • What they are: Pre-treatment units that aggressively aerate and biologically treat wastewater before it enters the drainfield.
  • When used: In soils with limited absorption capacity or stricter effluent quality requirements; can improve reliability in marginal soils.
  • Pros:
    • Higher levels of treatment can extend the life of the drainfield.
    • Some ATUs tolerate higher daily flows and challenging soils better than conventional systems.
  • Cons:
    • More complex and require ongoing maintenance and service contracts.
    • Electrical power and regular servicing are essential.
  • Maintenance essentials:
    • Regularly service and monitor per manufacturer guidelines.
    • Ensure alarms and timers are working; keep records of service visits.

Low-Pressure Dose (LPD) and pressure-distribution drainfields

  • How they differ: Use a pump, timer, and pressure-dosed lines to evenly distribute effluent to multiple absorption areas.
  • Why they're used: Helpful on sloped sites or limited soil where even distribution improves performance.
  • Pros:
    • More uniform loading across the drainfield.
    • Can accommodate irregular lot shapes.
  • Cons:
    • Requires power and a control panel; more components to maintain.
  • Maintenance basics:
    • Check the pump, timer, and control valve regularly.
    • Keep a service log and address clogs or leaks promptly.

Sand/Media Filter systems

  • What they are: A second-stage treatment bed or integrated filter that uses sand or other media to remove fine solids and pathogens before effluent enters the drainfield.
  • When they're used: In areas with higher soil infiltration resistance or when pretreatment is needed to meet higher effluent standards.
  • Pros:
    • Can improve effluent quality and protect the drainfield.
    • Flexible installation options for tough sites.
  • Cons:
    • Requires periodic media replacement or cleaning, depending on design.
  • Maintenance highlights:
    • Follow local inspection schedules; plan for occasional media servicing.
    • Keep surface area free of planting or heavy equipment that could disrupt the bed.

Official resources for McDowell County septic guidance:

  • North Carolina DHHS Onsite Wastewater Program:
  • North Carolina DEQ Onsite Wastewater Program:
  • NC Cooperative Extension Onsite Wastewater (general guidance):
  • U.S. EPA Septic Systems: https://www.epa.gov/septic

Typical Septic Issues Across McDowell County

Recognizing common signs homeowners notice

  • Odors near the septic tank or drain field, especially in wet or sunny spots.
  • Gurgling sounds in toilets or drains after use.
  • Slow drains, backups in sinks or tubs.
  • Patchy, soggy, or unusually green grass over the drain field.
  • Sewage backups inside the home during heavy use or rain events.

Most frequent causes in this area

  • Age and condition of the system: older tanks and failing baffles can allow solids to pass and clog the leach field.
  • Root intrusion: tree and shrub roots creep into pipes and tanks, causing leaks or blockages.
  • Overloading with water: long showers, laundry bursts, and disposal use can overwhelm the system.
  • Improper waste disposal: fats, oils, grease, chemicals, meds, or household cleaners can disrupt beneficial bacteria.
  • Soil and drainage challenges: clay soils, high groundwater, or seasonal saturation reduce drain-field performance.
  • Physical damage or compaction: heavy equipment or driving over the drain field compresses soil and interrupts drainage.

Drainfield and tank problems you may run into

  • Tank sludge and scum buildup that reduces volume and efficiency; regular pumping helps prevent this.
  • Broken or missing baffles allowing solids to flow into the drain field.
  • Cracked or collapsed tanks or pipes from age, freezing, or shifting soils.
  • Poor soil percolation or prolonged saturation: the field can no longer absorb effluent properly.
  • Tree roots blocking pipes or filling the absorption area, leading to backups or surface pooling.

Maintenance fundamentals you can rely on

  • Schedule professional inspections regularly. For many homes, a licensed septic contractor can assess both tank and drain field performance on a routine basis.
  • Pump every 3–5 years for typical households; more often if you have a garbage disposal, large family, or high wastewater load.
  • Use water efficiently: spread laundry across days, fix leaks, and install high-efficiency fixtures to reduce load on the system.
  • Keep the drain field protected: limit traffic, avoid placing heavy machinery or construction debris over the field, and plant only shallow-rooted vegetation nearby.
  • Use septic-safe products: avoid chemical drain cleaners; choose enzyme-based or septic-approved cleaners when possible.

Quick action plan if you suspect a problem

  1. Conserve water immediately: run full loads, avoid long showers, and limit simultaneous water use.
  2. Reduce wastewater input: suspend nonessential uses (garbage disposal, long baths) until inspected.
  3. Inspect visually: look for wet areas, foul odors, or slow drainage around the system.
  4. Avoid DIY fixes on the tank or field: call a licensed septic professional for a site assessment and pumping if needed.
  5. Schedule a professional evaluation promptly to prevent further damage and to determine if pumping, repair, or field replacement is necessary.

Local resources and official guidance

  • North Carolina Department of Environmental Quality (On-Site Wastewater Program) for state guidance, permits, and regulations:
  • U.S. Environmental Protection Agency septic care information and general guidance: https://www.epa.gov/septic

Septic Inspection, Permits & Local Oversight

Oversight in McDowell County

  • In North Carolina, septic system permits and inspections are overseen by the state's On-Site Wastewater program, with local county health departments handling fieldwork. In McDowell County, the Health Department administers residential on-site wastewater systems—site evaluations, plan reviews, and inspections.
  • Official guidance and look-up tools:
    • NC DEQ On-Site Wastewater Program:
    • Local health department lookup:

Cost Expectations for Septic Services in McDowell County

Septic Tank Pumping

  • What it includes: removing accumulated solids from the primary septic tank, cleaning baffles, inspecting the pump chamber (if present), and checking for any signs of leakage or distress. In older McDowell County homes, tanks are sometimes buried shallow or behind structures, which can affect accessibility.
  • McDowell County specifics: tighter access, rockier or sloped terrain can raise labor and equipment costs. Tanks in the 1,000–1,500 gallon range are common; larger tanks cost more to pump.
  • Typical cost in McDowell County: approximately $275–$550 per tank, depending on tank size, accessibility, and disposal fees.
  • How to prepare:
    1. Clear access to lids; two people may help.
    2. Have last pumping date and tank size handy.
    3. Schedule during dry weather to ease equipment positioning.
  • Official resources:

Septic System Inspections

Drain Field Evaluation and Repair

  • What it includes: soil testing or infiltration assessment, dye tests if needed, observing surface dampness, strength of effluent distribution, and overall field condition; repair options range from lateral line repair to full replacement.
  • McDowell County specifics: rocky or compacted soils can hinder drainage and may necessitate adaptive designs such as mound systems or upgraded distribution networks.
  • Typical cost ranges:
    • Evaluation: $300–$600
    • Repair (lateral lines, manholes, valves): $2,000–$8,000
    • Replacement/advanced systems (eg, mound): $10,000–$30,000+
  • When repair is considered: persistent wet spots, strong odors, septic effluent surfacing, or repeated pumpings without lasting improvements.
  • Official resources: https://www.epa.gov/septic'>https://www.epa.gov/septic, https://deq.nc.gov/about/divisions/waste-management/hw/onsite-wastewater-program

New System Installation

  • What it includes: site evaluation, design, permitting, soil and perc tests, trench layout, tank placement, and final start-up; in McDowell County, rock and depth to bedrock can influence design and cost.
  • McDowell County specifics: costs can be higher in rural, hilly, or rocky parcels; mound or alternative systems may be necessary in marginal soils.
  • Typical cost ranges:
    • Conventional system: $7,000–$15,000
    • Enhanced or mound system: $15,000–$40,000+
  • Steps in the process (brief):
    1. Site assessment and soil test
    2. System design and permits
    3. Installation and inspection
  • Official resources: https://www.epa.gov/septic'>https://www.epa.gov/septic, https://deq.nc.gov/about/divisions/waste-management/hw/onsite-wastewater-program

System Component Repair and Replacement

  • What it includes: pump replacement or repair, effluent filter maintenance, alarm replacements, lid and riser work, float switches, and control panels.
  • McDowell County specifics: remote locations may require additional hauling, longer labor, and sometimes specialized equipment for access.
  • Typical cost ranges:
    • Pump or float replacement: $1,200–$3,000
    • Alarm or control panel: $150–$600
    • Lid/riser replacement: $150–$600
  • Quick tips: replace worn components before failure to avoid field damage; keep spare parts on hand if you're in a remote area.
  • Official resources: https://www.epa.gov/septic

Camera/Diagnostic Sewer Line Inspections

  • What it includes: video inspection of interior lines from the home to the tank or field, identifying blockages, breaks, root intrusion, or offset joints.
  • McDowell County specifics: camera work is especially helpful on older or newly purchased homes with long or hidden lateral lines.
  • Typical cost: $150–$350, depending on length and access.
  • When to use: after repeated backups, before repairs, or as part of a comprehensive routine check.
  • Official resources: https://www.epa.gov/septic

Maintenance Plans and Routine Care

  • What it includes: annual or biannual service visits, system performance checks, pump/valve servicing, and reminder-based inspections to prevent major failures.
  • McDowell County specifics: rural homeowners often benefit from a simple, predictable maintenance plan to avoid costly emergencies.
  • Typical cost: $100–$250 per year, depending on service frequency and included tasks.
  • Best practices: keep accurate records, water-use awareness, and protect the drain field from heavy equipment and parking.
  • Official resources: https://www.epa.gov/septic

Cities & Communities in McDowell County With Septic Systems

Marion

Marion is the county seat and hosts the primary municipal sewer system in town limits. However, many homes and neighborhoods on the outskirts or outside the sewer service area rely on private septic systems.

  • Common setup: conventional septic tanks with drainfields, and some alternative systems in areas with challenging soils.
  • What this means for you: if your property isn't connected to Marion's sewer lines, you're likely on septic.

Maintenance and care

  1. Schedule regular pumping every 3–5 years (or per your system's size and usage).
  2. Protect the drainfield: keep foot and vehicle traffic off the area, and avoid planting trees or shrubs with deep roots nearby.
  3. Use water-efficient fixtures and spread out loads of laundry to reduce strain on the tank.
  4. Have a professional inspection whenever you're buying a home or when you notice damp spots, backups, or slow drains.

Resources to check

  • North Carolina Department of Environmental Quality (NCDEQ) Onsite Wastewater Program for standards, repairs, and guidelines:

Old Fort

Old Fort is a smaller community with a mix of sewer service and surrounding rural areas that rely on septic systems.

  • Typical scenario: homes inside town limits may have access to municipal sewer, while many properties just outside rely on septic.
  • Considerations: septic system condition is essential in older neighborhoods where soils and groundwater interactions can vary.

Maintenance and care

  1. Have septic tanks pumped every 3–5 years, adjusting for household size and tank capacity.
  2. Avoid flushing non-septic-safe materials ( fats, oils, chemicals, wipes) to protect the drainfield.
  3. Implement water-conscious habits to minimize frequent pumping.

Resources to check

Nebo

Nebo is an unincorporated area within McDowell County where septic systems are common for residential and small-lot homes.

  • Typical setup: a mix of conventional and alternative systems where soils aren't ideal or where space limits drainage fields.
  • Practical note: if you're in Nebo and connected to public sewer through nearby projects, your situation may differ; otherwise, plan for septic maintenance.

Maintenance and care

  1. Pump on a regular schedule based on tank size and family use.
  2. Protect the drainfield from compaction, heavy drainage, and invasive roots.
  3. Use septic-safe products and address leaks or running toilets promptly to prevent soil saturation.

Resources to check

Other rural and unincorporated areas (around Lake James and western McDowell County)

Beyond the named towns, many residents live in unincorporated neighborhoods and rural corridors where septic is the standard wastewater solution.

  • Typical situation: septic systems serve homes across these areas; municipal sewer is less common outside town centers.
  • Planning tips: if you're in one of these areas, your maintenance plan should be tailored to soil type, groundwater patterns, and lot size.

Maintenance and care

  1. Have a septic assessment performed if you're new to the property.
  2. Pump according to system type and usage; consider a professional inspection after significant weather events or flooding.
  3. Create a simple maintenance calendar and mark reminders for pumping, inspections, and lid access.

Resources to check

Note on official guidance

Septic vs Sewer Across McDowell County

Quick snapshot

In McDowell County, your choice often comes down to whether you're served by a public sewer system or rely on a private septic system. Sewer connections are usually found in towns and larger developments, with a monthly bill for service. Septic systems are common in rural areas and on properties not currently hooked to municipal lines, but they require ongoing maintenance to protect your home and the watershed.

Cost and maintenance trade-offs

  • Upfront vs ongoing costs: Sewer connection can involve a one-time hookup fee plus ongoing monthly charges. A septic system typically has higher upfront installation costs, followed by periodic maintenance rather than a monthly service bill.
  • Ongoing care: Sewer users pay for wastewater treatment through utilities; septic owners manage routine pumping, inspections, and field maintenance to prevent failures.
  • Maintenance requirements: Septic systems need regular pumping (every 3–5 years for many homes) and careful water use. Avoid dumping chemicals, grease, or non-biodegradable items into the system.

Site and environmental considerations in McDowell County

  • Land and soil: Drain-field size and soil percolation impact septic performance. Sloped, rocky, or shallow soils may limit septic effectiveness and require design tweaks.
  • Groundwater and wells: Proximity to wells, streams, or flood-prone areas matters for both septic design and safety. Proper setbacks and proper leachate management reduce contamination risk.
  • Climate and rainfall: Local weather patterns influence drainage and septic loading; heavy rains can affect drain fields if not properly protected.

What makes septic a good fit in McDowell County

  • Rural or semi-rural locations: If you're not within a sewered service area, septic is a practical, independent option.
  • Space and soil suitability: Homes with adequate land and properly treated soils can support a well-sized drain field and long-term performance.
  • Long-term cost control: With diligent pumping and maintenance, a well-managed septic system can be economical over decades, especially where sewer rates rise over time.

When sewer service is the better choice

  • Municipal service in your area: If you're in or near a town or serviced subdivision, sewer access eliminates the need for septic maintenance and reduces local groundwater risk from failed systems.
  • Limited space or poor soil: If your site won't support a reliable drain field, sewer may avoid costly remediation or repeated repairs.
  • Reliability and convenience: Sewer users benefit from professional wastewater treatment management and fewer on-site responsibilities.

Practical steps to compare options (clear, actionable)

  1. Check service availability: Contact McDowell County or your municipality to confirm whether public sewer is available at your property.
  2. Price out both paths: Gather up-front hookup costs, tap fees, and monthly sewer charges versus septic installation and expected pumping/maintenance costs.
  3. Assess site feasibility: Have a licensed septic designer review soil, lot size, groundwater depth, and drainage to estimate drain-field needs.
  4. Consider long-term risks: Weigh potential repair costs if a septic system fails versus ongoing sewer rate changes.
  5. Get professional input: Request quotes from a septic contractor and a sewer utility provider, and ask about local permitting requirements and inspection schedules.

Official guidelines and resources

  • NC Department of Environmental Quality – Onsite Wastewater Program:
  • U.S. Environmental Protection Agency – Septic Systems: https://www.epa.gov/septic