Septic in Litchfield, MI

Welcome to Litchfield, where country charm meets practical, everyday living. If you've driven a little farther off the main road to a cozy home with a bit more yard, you've probably seen the telltale signs of a septic system—the quiet workhorse tucked behind the house that keeps everything flowing smoothly without relying on a distant city sewer.

Is septic common in Litchfield? Should I expect septic if I own or buy a home? Yes to both. In Litchfield and the surrounding countryside, septic systems are the norm for most single-family homes that aren't connected to a municipal sewer line. Inside village limits you may indeed be on town sewer, but outside those boundaries, a septic system is the standard setup. If you're buying a home here, expect to find a septic system on most properties and plan for maintenance, inspection, and occasional pumping as part of owning the home.

Why do homes here typically use septic systems? A few practical reasons explain the high-level setup you'll see around town:

• Rural lot patterns: Many homes sit on larger lots where extending a sewer main isn't practical or cost-effective.
• Cost and practicality: A well-planned on-site system is often the most affordable, reliable way to handle wastewater for a single-family home in this region.
• Soil and groundwater realities: Michigan soils, when properly designed and installed, can filter and treat wastewater effectively, making septic a sensible option in many neighborhoods.
• Local independence: Septic systems give homeowners control over their own wastewater management, without depending on centralized infrastructure that may not reach every property.

High-level view of why septic exists here: Septic systems treat wastewater right on the property, using the soil to filter and break down contaminants. This on-site approach aligns with the area's development pattern—low-to-moderate density, more land per home, and the practical realities of building and maintaining widespread sewer lines in rural Michigan.

What this means for you as a homeowner or buyer in Litchfield: plan for regular care and smart usage. Typical guidance includes scheduling septic tank pumping every few years based on family size and usage, watching for warning signs like slow drains or odors, and partnering with a trusted local contractor for inspections and maintenance. A well-kept system helps your home stay comfortable and trouble-free for years to come.

Where Septic Systems Are Common in Litchfield

Rural, low-density layout

Litchfield is predominantly rural, with many homes on individual lots spread across agricultural and wooded land. Because most properties aren't connected to a municipal sewer, a septic system is the standard way households treat wastewater. This setup is common on farms, in neighborhoods with older single-family homes, and on parcels where septic permitting and maintenance are manageable for owners.

Soil and site considerations in Litchfield

Soils in the area can vary, and that variety shapes what septic systems work best. Key factors that influence siting and design include:

• Drainage: well-drained soils support typical drainfields, while slow-draining soils may require alternative layouts.
• Depth to groundwater: shallow water tables at certain times of year can limit drainfield size or require raised designs.
• Subsurface layers: rock fragments or dense clay can affect percolation rates and installation depth.

Because soil conditions differ from parcel to parcel, many Litchfield homes rely on a site-specific design approved by the local health authority.

Common septic system configurations you'll see in Litchfield

Most households use conventional systems, but some sites need alternatives. Typical configurations include:

• Conventional gravity systems with a buried septic tank and an underground drainfield.
• Raised or mound systems when soils are slowly permeable or when the seasonal water table is high.
• Sand or infiltrative filters as a secondary treatment option on challenging sites.
• Enhanced maintenance components (e.g., effluent filters, properly sized pumps) to improve reliability on marginal soils.

Setbacks, protection, and compliance

Wastewater systems must be sited and protected to avoid contamination of wells, streams, and neighboring lots. Local health departments enforce setback requirements and inspection standards, and state rules govern design, installation, and pumping intervals. For authoritative, location-specific guidance, refer to:

• EPA Septic Systems: practical, nationwide guidance on siting, maintenance, and warnings of common problems.

Septic vs Sewer: What Homeowners in Litchfield Should Know

Quick distinctions

• Septic system: an on-site option that treats wastewater in a tank and soil absorption field on your property. You're responsible for maintenance, pumping, and managing the drain field.
• Municipal sewer: a centralized system owned by the city or county that carries wastewater to a treatment plant. You pay monthly service fees and the utility manages treatment and system maintenance.

In Litchfield, MI, many rural homes rely on septic, while nearby villages and townships may have or expand sewer service. Knowing which option applies to you helps with budgeting, maintenance, and long-term planning.

How to know what you have in Litchfield

1. Check with your local authority
2. Contact Litchfield Township offices or the Hillsdale County Water and Waste Department to confirm whether sewer service is available at your address or if you're currently on a septic system.
3. Review documents
4. Look at property records, your water/sewer bill (if any), or home inspection files from when you bought the place.
5. Inspect what you pay for
6. A sewer bill indicates a connection to a municipal system; the absence of a monthly sewer bill and the presence of a septic tank lid or a drainage field points to a septic system.
7. Hire a professional if unsure
8. A licensed plumber or septic contractor can verify the system type and provide a formal assessment.

Pros and cons at a glance

• Septic system
  • Pros: Private control, potential long-term cost savings if well maintained; suitable for rural lots without sewer lines.
  • Cons: Regular pumping and maintenance required; failures can be costly and impact groundwater and soil health.
• Municipal sewer
  • Pros: Utility handles maintenance and repairs; no private drain-field concerns.
  • Cons: Connection costs if not already connected; ongoing monthly fees regardless of usage; potential for rate increases over time.

Availability and planning in Litchfield

• Rural areas nearby may not have a sewer main nearby; expansion depends on funding, permitting, and pipe routing.
• If sewer is available, there are typically connection deadlines, fees, and required upgrades to internal plumbing and backflow prevention.
• If you're on septic and sewer becomes available, you'll need to evaluate the cost and process to connect, decommission the septic system, and transfer wastewater management to the public system.

Costs to plan for

• Septic system ownership (typical ranges, varies by lot and system design):
  • Installation or replacement: roughly $10,000–$25,000+
  • Annual maintenance and pumping: $300–$600 every 3–5 years (varies)
• Sewer connection (if available):
  • Connection fee: commonly $2,000–$6,000 or more (local rules vary)
  • Monthly sewer usage charges: roughly $30–$60+ depending on local rates
  • Possible internal plumbing updates to meet code or backflow prevention requirements
• Long-term considerations: environmental compliance, inspection frequencies, and potential system upgrades if local regulations change

Maintenance and longevity

• For a septic system:
  • Pump every 3–5 years (earlier for homes with high water use or backups)
  • Conserve water; spread out heavy use
  • Protect the drain field: avoid driving or parking on it, plant only shallow-rooted vegetation, and keep out chemicals, fuels, and non-biodegradables
  • Use septic-safe products and enzymes as recommended by a pro
• For sewer:
  • Schedule routine inspections or needed repairs through the municipal utility
  • Monitor for notices about sewer backups, blockages, or maintenance windows

Official resources and next steps

• EPA Septic Systems overview: https://www.epa.gov/septic
• Michigan EGLE (state environmental/regulatory information): https://www.michigan.gov/egle
• Local guidance
  • Litchfield Township office or Hillsdale County Water and Waste Department for address-specific availability and requirements
• Consult a licensed professional
  • A local septic contractor or plumber can perform inspections, provide cost estimates, and guide you through any required connections or decommissioning steps if you switch from septic to sewer.

Typical Septic System Types in Litchfield

Conventional gravity septic systems

A traditional setup where wastewater flows from the house into a buried septic tank, then leaches to a soil absorption field (drain field) by gravity. This is the most common type for many Litchfield homes.

• How it works: solids settle in the tank; clarified liquids exit to perforated pipes in trenches or beds buried in soil.
• Site needs: adequate soil depth, good permeability, and enough room for the drain field.
• Pros: simple design, generally lower upfront cost, easy to maintain.
• Cons: performance depends on soil conditions; overuse or poor maintenance can clog or fail the drain field.

Chamber or bed drain-field systems

A modern variation that uses prefabricated plastic chambers instead of traditional gravel-filled trenches.

• How it works: wastewater exits the tank into a shallow chambered field that distributes effluent across the soil.
• Benefits: lighter weight, faster installation, often more space-efficient than gravel beds.
• Best for: sites with limited space or where contractors prefer chamber technology.
• Considerations: still soil-dependent; proper design and zoning are essential.

Mound systems

Engineered structures built above natural grade when native soils are shallow, highly compacted, or poorly suited for drainage.

• Why they're used: high groundwater, bedrock, or very poor soil infiltration.
• How it works: a sand fill layer creates a perched area for the drain field above the natural soil.
• Pros: allows septic treatment in challenging soils; can extend residential use on restricted lots.
• Cons: higher initial cost, more monitoring, and more frequent maintenance checks.

Aerobic Treatment Units (ATU) with dose or discharge to drain field

ATUs provide advanced treatment before the effluent reaches the drain field, often with mechanical aeration and sediment separation.

• How it works: aerobic treatment for a higher-quality effluent; treated liquid then enters a drain field or nearby disinfection step.
• When used: poor soils, restrictive lots, or higher-strength wastewater (e.g., from certain appliances).
• Pros: improved effluent quality, can reduce drain-field size needs.
• Cons: electricity use, more components to service, ongoing professional maintenance required.

Sand filter systems

An elevated, controlled filtration bed that provides an additional treatment step where soil conditions aren't ideal.

• How it works: effluent from the septic tank or ATU passes through a sand filtration layer before reaching the soil.
• Pros: can improve treatment in marginal soils; helps with odors and residue control.
• Cons: more complex to install and maintain; requires regular inspection of the media.

Drip dispersal and low-pressure dosed (LPD) systems

These systems distribute effluent slowly through small, pressurized lines to improve soil infiltration.

• How it works: a pump and dosing chamber apply effluent in small doses to multiple distribution lines.
• Pros: better performance on restrictive soils; more uniform percolation.
• Cons: higher upfront cost, more precise design and professional upkeep needed.

Holding tanks and cesspools (less common in residential Michigan)

Some older or temporary setups may still exist, but they are not typical for new construction.

• Holding tanks: store wastewater and require regular removal by a tank contractor.
• Cesspools: solids and liquids accumulate in a pit without a formal leach field; often phased out or restricted.
• Important: verify with your local health department before choosing or replacing any of these options.

Maintenance and monitoring across all types

• Inspect and pump on a schedule tailored to your system and household usage.
• Protect the drain field: avoid parking, heavy equipment, and deep-rooted trees or shrubs over the area.
• Conserve water to reduce load on the system.
• Schedule periodic professional evaluations, especially after major renovations or if you notice signs of trouble (gurgling, backups, or damp spots).

What to do next

• Have a licensed septic professional assess your site to determine the best-fit system type for your soil and lot in Litchfield.
• Keep records of all service visits, pump-outs, and system changes.

Official guidance and resources

• Michigan Department of Environment, Great Lakes, and Energy (EGLE): Onsite Wastewater Program – official state guidance and requirements (https://www.michigan.gov/egle)
• EPA Septic Systems overview – general, non-state-specific best practices and maintenance tips (https://www.epa.gov/septic)

Common Septic Issues in Litchfield

Soil and drainfield limitations common in Litchfield

• Litchfield-area soils can be heavy with clay and compacted subsoil. This reduces infiltrative capacity, leading to slower drainage, surface dampness, and backups even when the tank is functioning.
• Seasonal moisture and occasional groundwater rise can saturate the drainfield, especially after wet springs or rapid snowmelt.
• Why it matters here: clay-rich soils and variable moisture are more likely to create perched water conditions, shortening drainfield life if the system isn't sized or managed for those conditions.

What to look for

• Persistent wet spots or lush vegetation over the drainfield.
• Slow drains, gurgling toilets, or toilets that back up after several loads of laundry.

Mitigation steps

• Avoid heavy landscaping or construction over the drainfield; keep vehicles off the area.
• Have the drainfield evaluated by a licensed septic professional who can recommend soil tests and even alternative designs if needed.

Water table and seasonal flooding

• High groundwater in parts of Hillsdale County can push effluent closer to the soil surface during spring thaws.
• Excessive water use (heavy irrigation, multiple loads of laundry, long showers) can saturate the soil and overwhelm the leach field.

What to do

• Space out water-intensive activities, particularly during wet periods.
• Schedule a professional evaluation if you notice standing water, slow drainage, or strong odors near the system.
• If your site is prone to saturation, a professional may suggest an alternative drainfield design (such as a mound system or dosing/pressurized distribution) to keep effluent above saturated soils.

Tree roots and landscape interference

• Roots from pines, maples, oaks, and other mature trees can invade septic trenches or the drainfield, causing blockages or physical damage.
• In Litchfield, many homes sit amid mature landscaping and tree-lined lots, increasing the risk of root intrusion over time.

How to protect it

• Plant buffer zones away from the drainfield and tank; consider root barriers when placing landscaping.
• Regularly inspect the area for growing roots and have any encroaching roots removed by a professional if they threaten the system.

Aging systems and improper maintenance

• Septic components (tank, baffles, distribution box) wear out. In older Litchfield homes, failed baffles or cracked tanks are not uncommon.
• Pumping frequency may be off due to changes in household size, water usage, or failed components, accelerating system deterioration.

Maintenance tips

• Have a licensed inspector assess tank integrity, baffles, and the distribution system every 3–5 years, or sooner if you notice problems.
• Pump every 3–5 years for a typical family, or per a professional's recommendation based on tank size and usage.
• Use water wisely and avoid sending fats, oils, greases, medications, wipes, and chemicals into the system.

Odors, backups, and surface seepage

• Odors in the home or yard, gurgling sounds, or surfacing effluent indicate a stressed or failing system.
• In Litchfield, seasonal moisture and soil conditions can make odors more noticeable when the drainfield isn't absorbing efficiently.

What to do if you notice symptoms

• Minimize water usage and postpone nonessential wastewater generation.
• Schedule a site assessment with a licensed septic professional to diagnose tank integrity, leach field health, and soil conditions.
• If needed, plan for tank repair, baffle replacement, or drainfield redesign with proper permitting.

Local resources and guidance

• For general guidance on septic systems, see EPA's Septic Systems page: https://www.epa.gov/septic
• For Michigan-specific information and regulatory context, visit Michigan EGLE: https://www.michigan.gov/egle

Symptoms to watch for (quick reference)

• Slow drains, frequent backups, or toilets that refill slowly
• Wet spots, lush vegetation, or strong odors over the drainfield
• Gurgling noises in plumbing or repeated need for pumping beyond expected intervals

Septic Inspection, Permits & Local Oversight

Permits you typically need

• New septic system installation, major repairs, or replacement usually requires a county health department permit.
• Design plans and soil evaluations often must be reviewed before work begins.
• In some cases, a local building permit is also needed, so check with the village or township authority.

Who administers permits in Litchfield, MI

• In Litchfield (Hillsdale County area), onsite wastewater permits are typically handled by the local county health department on behalf of the state. Start by contacting Hillsdale County Health Department to confirm current requirements, establish the right permit type, and schedule inspections.
• If you're unsure who to contact, your local assessor or the county clerk can point you to the correct health department office. Official state resources can also help you locate the right authority: Michigan EGLE (Onsite Wastewater) and the state health directory.
• Official resources:
  • Michigan EGLE:

How inspections work

• Three common stages:
  1. Pre-installation/site evaluation and design review (planning phase).
  2. Installation inspections during key phases (grading, trenching, tank placement, piping, backfill).
  3. Final inspection and system startup verification (proper dosing, inspection ports accessible, documentation filed).
• Inspections are typically scheduled through the health department or designated inspector. Have the system plan, approved permit, and licensed contractor ready for review.

Real estate transfers and disclosures

• Septic inspections are highly recommended during real estate transactions. Some lenders or local ordinances require a current septic assessment, a pumping record, or a dye test.
• Seller and buyer should agree on who pays for the inspection and how any deficiencies will be addressed. Your real estate agent can help coordinate with the health department and inspectors.

Working with licensed professionals

• Hire a Michigan-licensed septic designer/installer (and a licensed pumper for maintenance). They will help with the permit application, plan submission, and inspection scheduling.
• Confirm the installer will coordinate with the county health department to obtain the permit and to arrange required inspections.
• Keep copies of all permits, plans, inspection reports, and maintenance records in a central place.

What to expect during inspections

• Inspectors verify tank accessibility (lids or risers), tank condition and baffles, proper pump/effluent piping, cleanouts, and the leach field's condition and setback distances.
• They may check for proper water use, verify that dosing siphons or pumps are configured correctly, and look for signs of system failure (backups, surfacing effluent, strong odors).
• If issues are found, you'll typically be given a list of required corrections and a deadline to complete them before final approval.

Quick readiness checklist

• Locate and label the septic tank(s) and access ports; ensure lids are visible and accessible.
• Clear the area around the tank and leach field to allow easy inspection.
• Gather maintenance records, past pumping dates, and any repair work done since installation.
• Ensure any required permits or plan approvals are on site and accessible to the inspector.

Licensed professionals and permits: quick tips

• Verify licenses and check for any disciplinary actions with the Michigan licensing board.
• Ask for references and confirm they will handle permit submissions and inspection coordination.
• After work is complete, keep all final inspection approvals and certification documents with your home records.

Septic Maintenance for Homes in Litchfield

Litchfield climate and soil considerations

• Litchfield winters bring freezing temps and rapid thaw cycles. These conditions can stress drainage fields and tune-ups become more important after heavy snowmelt.
• Spring moisture and a fluctuating water table can push effluent closer to the surface. If you notice damp patches, lush green areas, or strong odors near the drainfield, schedule a professional check.
• Soils around Hillsdale County vary. Heavy clay or shallow soils slow infiltration and push systems to work harder. If your lot has wet areas, poor drainage, or known groundwater problems, plan for more frequent inspections and a tailored maintenance approach.
• For official Michigan guidance on site evaluation, design, and maintenance, see the Michigan EGLE Onsite Sewage Disposal Systems resources:

Regular maintenance schedule

1. Pumping interval
2. Typical homes with normal usage: pump every 3–5 years.
3. Larger households, frequent guests, or aging tanks may require 2–3 year pumping.
4. If you're unsure, have a licensed septic pro assess tank size and condition during a service visit.
5. Annual inspections
6. Have a licensed septic contractor inspect the tank, baffles, and any effluent filters each year.
7. Ask for a check of sludge and scum levels, and confirm there are no cracks or leaks in the tank or piping.
8. Water-use management
9. Repair leaks promptly and install high-efficiency toilets and fixtures when possible.
10. Space out laundry loads, and use low-flow settings to reduce hydraulic load on the system.
11. Spread out heavy water use (e.g., wash cycles) to avoid overloading the tank in a single day.
12. Pump-out logistics
13. When scheduling pumping, have the contractor inspect the distribution box and drainfield condition.
14. If you have an effluent screen or filter, ensure it's cleaned during service to prevent clogs.

Drainfield care and landscape

• Limit traffic over the drainfield: no vehicles, heavy equipment, or full-grown landscape changes directly on the area.
• Plant with care: shallow-rooted grasses and shrubs are generally safer; avoid deep-rooted trees within 20–30 feet of the drainfield when possible.
• Irrigation and surface drainage: direct sprinklers away from the drainfield and maintain positive drainage so standing water doesn't sit on the system.
• Fertilizer use: keep fertilizers and yard chemicals away from the drainfield. Use slow-release fertilizers sparingly and only as needed.

What to flush and what to avoid

• Flush only: human waste and toilet tissue.
• Avoid flushing: wipes (even "flushable"), diapers, feminine hygiene products, cat litter, paper towels, medications, chemicals, oils, paints, solvents, and other household chemicals.
• Household cleaners: choose septic-safe products and avoid antibacterial formulas that kill beneficial bacteria in your tank.
• Be mindful of cooking fats: pour fats and oils into a container and dispose of them in the trash, not the sink.

Signs of trouble and what to do in Litchfield

• Common red flags: slow drains, gurgling toilets, sewage odors, wet or lush patches over the drainfield, or sewage backup in fixtures.
• Action steps: avoid aggressive chemical use or attempting DIY fixes that require opening the tank; call a licensed septic professional for a diagnostic and potential pumping or field inspection.
• After heavy rains or rapid spring melt in this region, watch for drainage changes and consider a proactive inspection if you notice damp areas or smells.

Resources and references

• Michigan EGLE Onsite Sewage Disposal Systems:
• EPA Septic Systems overview: https://www.epa.gov/septic

Cost Expectations for Septic Services in Litchfield

Septic Tank Pumping and Cleaning

• What it includes: removing solids from the bottom and scum from the top of the tank, inspecting lids and risers, checking baffles and inlet/outlet pipes, and ensuring adequate access for future maintenance.
• Litchfield specifics: rural homes with gravity systems and older clay soils can influence pump size and frequency; larger tanks (1,000–1,500 gallons) are common and may cost more to pump.
• Typical cost in Litchfield: roughly $250–$500 per pumping; $350–$600 if additional services (filter cleaning, multiple tanks, or difficult access) are needed.
• Quick note: many homes in Litchfield schedule pumping every 3–5 years depending on usage and tank size.
• Resources: EPA septic information: https://www.epa.gov/septic

Septic System Inspection

• What it includes: visual inspection of the tank, lids, and access risers, assessment of the drain field's condition, odor checks, and basic functionality; may include a dye test or camera inspection for thoroughness, especially during real estate transactions.
• Litchfield specifics: real estate or loan requirements may drive a more comprehensive inspection; spring rain can affect surface indicators.
• Typical cost in Litchfield: basic inspection $100–$300; more thorough evaluations with camera or dye tests $300–$600.
• Quick note: inspections help identify problems before they become costly repairs.
• Resources: EPA septic information: https://www.epa.gov/septic; Michigan EGLE overview: https://www.michigan.gov/egle

Drain Field Evaluation and Repair

• What it includes: soil moisture probes or tests to gauge absorption, evaluation for wet areas or surface sogginess, and inspection of distribution boxes and trenches; repairs may involve replacing damaged drain lines, relocating or rebuilding sections of the field.
• Litchfield specifics: soil type and seasonal groundwater influence field performance; rural lots may require longer or alternative-field designs.
• Typical cost in Litchfield: field evaluation $200–$500; repairs $2,000–$8,000; full drain-field replacement $7,000–$25,000; mound systems or complex designs $20,000–$40,000+.
• Quick note: cost spikes with extensive soil issues or when permit-required redesigns are necessary.
• Resources: EPA septic information: https://www.epa.gov/septic

Septic System Installation/Replacement

• What it includes: site evaluation, design, permits, excavation, tank installation, drain-field installation (gravity or pressure distribution), backfilling, system start-up and testing.
• Litchfield specifics: rural lots with challenging soils may require alternative systems (e.g., mound or ATU) and additional permitting steps.
• Typical cost in Litchfield: conventional gravity systems $10,000–$25,000; mound or alternative systems $20,000–$40,000; advanced treatment options $15,000–$50,000+, plus 5–15% of total for permits/engineering.
• Quick note: a replacement often involves removing an old tank and possibly partial site work.
• Resources: EPA septic information: https://www.epa.gov/septic; Michigan EGLE overview: https://www.michigan.gov/egle

Septic System Repairs

• What it includes: fixes to cracked tanks, broken baffles, collapsed or leaking pipes, root intrusion, and distribution box problems; may require excavation and resealing.
• Litchfield specifics: access in rural yards and older systems can drive labor time and cost.
• Typical cost in Litchfield: minor repairs $1,000–$2,500; moderate $2,500–$6,000; major repairs (tank replacement or field remediation) $8,000–$25,000+.
• Quick note: timely repairs prevent more extensive damage and avoid emergency service premiums.
• Resources: EPA septic information: https://www.epa.gov/septic

Aerobic Treatment Units (ATUs) and Other Advanced Systems

• What it includes: installation or upgrade of ATU components, aeration equipment, discharge controls, and supplemental treatment; routine maintenance is required to keep performance up to code.
• Litchfield specifics: suitable for challenging soils or limited drain-field area; some properties may rely on ATUs to meet local setback and effluent requirements.
• Typical cost in Litchfield: ATU unit and install $5,000–$12,000; complete system with controls $12,000–$25,000; annual maintenance $150–$500.
• Quick note: advanced systems often come with annual service contracts.
• Resources: EPA on ATUs: https://www.epa.gov/septic

Permits, Inspections, and Local Requirements

• What it includes: permit applications, site evaluations by the local health department, installation inspections, and final system approval; Hillsdale County Health Department handles local permitting and inspections in Litchfield.
• Typical costs: permit fees often range $100–$500 depending on system type; inspection fees may be included with installation or charged separately.
• Quick note: check with the Hillsdale County Health Department for current fee schedules and required steps.
• Resources: Hillsdale County Health Department (local authority); EPA septic information: https://www.epa.gov/septic

Tips for getting accurate quotes

• Get at least 3 written estimates.
• Confirm tank size, system type, and access considerations.
• Ask about all potential charges: permits, dye tests, camera inspections, accessibility, and seasonal rates.
• Verify licenses, insurance, and any local references.
• Request a written maintenance plan and recommended pumping interval.

Official resources

• EPA: https://www.epa.gov/septic
• Michigan EGLE: https://www.michigan.gov/egle
• EPA guidance on ATUs: https://www.epa.gov/septic