Septic in Monticello, MN

Last updated: Mar 21, 2026

Welcome to Monticello, where friendly neighbors, a strong sense of community, and practical home care go hand in hand. Your septic system is part of that everyday stewardship—something you'll rely on and ideally maintain with a bit of neighborly know-how.

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

In Monticello, septic status mostly comes down to location and the age of the property. If your home is inside the municipal sewer service area, you'll typically be connected to city sewer and won't have a private septic tank. If you're on a larger lot outside the sewer district, or you're looking at an older home in a rural or fringe area, a private septic system is common and often required. When you're buying, it's wise to confirm with the seller and the city or county records whether the home uses sewer or a septic system, and to check the age and condition of any septic system that's on the property.

Why homes typically use septic systems in Monticello

Monticello's growth includes a mix of newer developments and rural parcels where a centralized sewer line isn't practical or available to every lot. Septic systems provide a practical, cost-effective way to manage wastewater on sites where extending sewer mains isn't feasible. The system design and maintenance must align with local rules to protect groundwater and the environment, which matters in Minnesota's climate and varied soils. In short, septic exists here because it's a sensible, on-site solution for many Monticello homes, especially those outside the main sewer corridors or on properties with specific lot sizes.

High-level overview: how septic helps a Monticello home

  • It's a private, on-site wastewater solution that supports homes not connected to city sewer.
  • Proper design, installation, and maintenance ensure safe wastewater treatment and soil absorption.
  • Regular maintenance—think pumping, inspection, and avoiding harmful substances—extends the life of the system and protects your property value.

Maintenance at a glance

  • Pump every 3–5 years for typical family use.
  • Mind the water; spread out loads and fix leaks to protect the drain field.
  • Use septic-safe products and avoid disposing of fats, oils, and harsh chemicals.
  • Schedule periodic inspections, especially after major repairs or if you notice slow drains or odors.

A practical, neighborly note: I'm here to help you navigate Monticello's septic basics with clear guidance and dependable service. With that in mind, you'll find practical steps that keep your system running smoothly in this community.

Where Septic Systems Are Common in Monticello

Map of septic coverage in Monticello, MN

Areas outside the city sewer service boundaries

  • Rural residential parcels on the outskirts of Monticello are the most likely to rely on on-site septic systems. When municipal sewer lines don't extend far enough to cover these properties, septic remains the practical and cost-effective option.
  • Subdivisions developed before widespread sewer expansion may still use individual systems if sewer mains weren't installed or extended at the time of construction.
  • For lake-adjacent properties, shoreland regulations and practical limitations can keep septic as the default option, especially where extending sewer lines is challenging or cost-prohibitive.

Why septic persists in these parts

  • Cost and logistics of extending sewer: Building and maintaining long sewer mains through varied terrain, herbaceous borders, and wetland areas can be expensive, so many properties stay on on-site systems.
  • Lot size and layout: Larger lots common in rural and semi-rural Monticello provide room for conventional septic systems or mound designs without encroaching on structures, wells, or setbacks.
  • Local service maps and planning: Not every neighborhood sits inside a defined sewer district, so septic remains common where service is not planned or funded in the near term.

Soil, water, and lot-size factors that support septic

  • Soil type matters: Sandy or well-drained soils can support traditional septic leach fields, while poorly draining soils may require alternative designs (like mound systems) designed by a licensed professional.
  • Groundwater and well separation: Minnesotan regulations emphasize separation between wells and septic components. Where water wells are present, proper setback distances and design are essential, making on-site systems a practical choice in some layouts.
  • Maintenance realities: In areas with frequent seasonal wetness or shallow bedrock, regular maintenance and professional design help septic systems perform reliably, which keeps on-site systems viable in many Monticello locations.

Lakes, wetlands, and shoreland considerations

  • Shoreland districts often influence system placement, setback distances, and field activities to protect lake water quality. In many Monticello lake areas, homeowners keep using on-site systems with appropriate design standards and maintenance.
  • Mitigation and treatment options: When shoreland or environmental rules apply, homeowners may opt for enhanced treatment units, properly sized fields, or other code-compliant solutions to minimize nutrient loading.

How to verify your property's status (quick steps)

  1. Check the City of Monticello sewer service status for your address on the city's official site. City resources:
  2. MPCA Onsite Wastewater:
  3. Consult a licensed septic professional for a site evaluation and design if you're planning a new system or upgrading an existing one. They can confirm whether your lot and soils are suitable for conventional septic, mound systems, or alternative technologies under current codes.

Quick neighborhood patterns to watch

  • Rural edge lots: Higher likelihood of septic if there's no nearby sewer main.
  • Lakeside parcels: Shoreland rules influence placement, but on-site systems remain common with proper setbacks.
  • Older subdivisions: Septic usage persists where sewer mains were not extended during initial development.
  • Areas with variable soils: Design choices (percolation rates, depth to groundwater) guide whether standard fields or elevated systems are used.

Official resources referenced, as applicable to Monticello residents:

Septic vs Sewer: What Homeowners in Monticello Should Know

How the two systems work

  • Septic system (on-site) removes and treats wastewater on your property. Wastewater flows from your home into a septic tank, where solids settle, then into a drainfield where soil and bacteria complete the treatment.
  • Public sewer (municipal) collects wastewater from multiple homes via a network of pipes and sends it to a municipal treatment plant for processing. Homeowners pay a monthly sewer bill and rely on the city's infrastructure for disposal.

Which option applies to Monticello?

  • Many Monticello homes are connected to municipal sewer, while some rural or fringe properties rely on on-site septic systems. If you're unsure which system serves your address, start with a quick check of your property's service records or contact the City of Monticello public works or the local utility. For official guidance on septic systems, see state resources below.

Costs and financial considerations

  • Septic system installation and replacement
    • Typical range: roughly $8,000 to $25,000, depending on tank size, soil conditions, and required permits.
    • Ongoing maintenance: pumping every 3–5 years is common; costs vary by contractor and tank size.
  • Connecting to municipal sewer
    • One-time hookup fees or assessments may apply, plus regular monthly sewer charges on your utility bill.
    • In some neighborhoods, upgrades or expansions to the sewer system can influence timing and costs.
  • Long-term value
    • A well-maintained septic system protects your property value; improper maintenance can lead to costly repairs and environmental issues.
    • Public sewer connections can simplify maintenance but introduce ongoing utility costs.

Maintenance basics you can implement

  • Schedule and track regular pumping and inspections
    1. Have your septic tank pumped by a licensed contractor every 3–5 years (or more often with large families or heavy disposal usage).
    2. Arrange annual or interval inspections to catch issues before they become costly.
  • Protect the drainfield
    • Keep heavy equipment and vehicles off the drainfield area.
    • Plant only shallow-rooted vegetation over the drainfield to avoid root intrusion.
    • Direct surface water away from the drainfield to prevent saturation.
  • Mind what goes down the drain
    • Use water-saving fixtures to reduce load.
    • Avoid flushing wipes, oils, solvents, paint thinners, and harsh chemicals.
    • Dispose of fats, oils, and grease in the trash, not the sink.
  • When in doubt, call a pro
    • If you notice backups, gurgling, slow drains, foul odors, or damp spots in the yard, contact a licensed septic contractor or your local public works department for guidance.

Signs you may need service or a connection assessment

  • Slow drains, frequent backups, or foul odors near plumbing or the drainfield.
  • Wet or unusually lush areas in the yard over the drainfield, or standing water after rain.
  • Gurgling sounds in plumbing or toilets that drain slowly.

Helpful, official resources

  • Minnesota Department of Health: Onsite Wastewater Treatment Systems (OSWTS) and guidance for septic maintenance
  • U.S. Environmental Protection Agency: Septic systems information and homeowner tips
  • For local service details and sewer availability, you can also check the City of Monticello's public works resources

Typical Septic System Types in Monticello

Conventional septic systems (gravity)

  • How they work: Wastewater leaves the building, collects in a septic tank, and effluent flows by gravity into a drainfield or leach field. Simple, reliable, and common where soils drain well.
  • Site needs: well-drained soil, adequate depth to groundwater, and enough room for a drainfield.
  • Maintenance basics: have the tank pumped every 3–5 years (typical range; your local inspector can confirm). Protect the drainfield from heavy equipment, roots, and parking.
  • Pros: lower upfront cost, fewer moving parts, straightforward design.
  • Cons: less forgiving in poorly draining soils or high water tables; failure leads to backups or soggy drainage areas.
  • Official resources: MPCA on-site wastewater treatment systems (OWTS) overview:

Pressure-dosed and mound systems

  • Why they're used: when soils are shallow, clayey, or have seasonal high water, gravity alone won't reliably distribute effluent. A small pump chamber intermittently distributes effluent to a shallow or elevated drainfield.
  • What to expect: a pressure-dosed network or a raised "mound" of sand above natural grade. Mounds expand usable area and improve treatment in marginal soils.
  • Maintenance notes: requires a pump, regular service of controls, and routine inspection; ensure power supply and vents are clear.
  • Pros: works in less-than-ideal soils; protects water quality when the native soil isn't ideal.
  • Cons: higher cost; more components to maintain.
  • Official resources: MPCA guidance on alternative systems (including mound and pressure-dosed designs):

Sand filter systems

  • What they are: effluent from the septic tank goes to a sand-based treatment bed where filtration helps remove contaminants before reaching the drainfield.
  • Site needs: often used when native soils don't provide adequate treatment, but space for a filter bed is required.
  • Maintenance notes: periodic backwashing or flushing of filters (per system design) and routine pumping of the tank.
  • Pros: reliable additional treatment in challenging soils.
  • Cons: larger footprint and ongoing maintenance costs.
  • Official resources: MPCA guidance on advanced treatment systems (sand filters included in the broader category): https://www.pca.state.mn.us/waste-management/onsite-wastewater-treatment-systems

Holding tanks and seasonal systems

  • Situations: used where continuous discharge isn't practical (seasonal properties, properties with very limited wastewater generation, or when a drainfield isn't feasible).
  • Maintenance: regularly pumped and inspected; must be disposed of promptly to prevent odors and overfill.
  • Pros: avoids ongoing drainfield issues when full-system installation isn't possible.
  • Cons: not a long-term substitute for a proper drainfield; requires careful management and regular disposal.
  • Official resources: MDH and MPCA documents on wastewater systems and seasonal properties: https://www.health.state.mn.us/communities/environment/wastewater/index.html

Shared or clustered systems (community or lot-wide)

  • Who uses them: in some developments, a single treatment system serves multiple homes, with a centralized drainfield or filtration stage.
  • Considerations: shared responsibility, ongoing maintenance contracts, and adherence to inspections.
  • Maintenance tips: ensure every user understands pumping and waste-disposal guidelines; maintain access for service.
  • Official resources: MPCA overview of onsite wastewater management and community systems: https://www.pca.state.mn.us/waste-management/onsite-wastewater-treatment-systems

How to know which type you have (quick steps)

  1. Locate the access lid or designation on your property and check your permit or as-built drawings.
  2. Review any recent inspections or maintenance reports from your local health or building department.
  3. Talk to the licensed septic designer or installer who last worked on the system.
  4. If in doubt, hire a qualified septic professional to perform a site evaluation and system diagnosis.
  5. Maintenance mindset: no matter the type, plan for regular pumping, protective landscaping, and mindful water use to extend system life. For references and official guidelines, consult MPCA and MDH resources above.

Common Septic Issues in Monticello

Flood-prone soils and high water table

Monticello sits in areas where the groundwater can be close to the surface, especially after heavy rains or spring thaws. Floodplain and high-water-table conditions slow down drain-field drainage, increase the chance of effluent surfacing, and raise the risk of backups.

  • Symptoms to watch for: lingering wet spots above the drain field, sweet or sewage odors in the yard, gurgling toilets, or toilets that back up during wet seasons.
  • Why Monticello-specific: certain neighborhoods near the Mississippi/Mississippi-adjacent flats have soils that don't drain well naturally, so a standard drain field can stay saturated much of the year.
  • What to do:
    1. Have a licensed septic professional evaluate your system, especially if backups occur after rainstorms.
    2. Reduce wastewater load during wet periods (avoid unnecessary irrigation, long showers, and loads of laundry).
    3. If drain-field saturation is chronic, discuss options with a pro (raised/raised-bed or mound systems, additional dosing, or relocating the field if feasible).

Resources:

  • MPCA Onsite Wastewater Systems (OWTS) guidance:
  • Minnesota Department of Health Onsite Wastewater guidance:
  • University of Minnesota Extension Septic Systems overview:

Clay soils and slow drainage

Stiff, clay-heavy soils common in some Monticello zones drain poorly and can keep a saturated drain-field even when the rest of the yard looks dry. Perched water and slow infiltration reduce the drain-field's ability to treat wastewater effectively.

  • Symptoms: persistent damp patches, foul odors near the leach field, and sluggish drainage in sinks and toilets.
  • Why Monticello-specific: clay layers and compacted ground in several subdivisions can create perched conditions above the drain field.
  • What to do:
    1. Have soil and percolation rates tested to confirm infiltration capacity.
    2. If infiltration is poor, consider alternatives (raised beds or mound systems) designed for low-permeability soils.
    3. Maintain proper setbacks from driveways, trees, and foundations to keep the field from being compromised by pavement or roots.

Resources:

Tree roots and landscaping near the drain field

Roots from mature trees and shrubs can intrude into buried lines and distribute pipes, leading to blockages, backups, or cracked lines. Monticello neighborhoods with established landscaping are particularly at risk.

  • Symptoms: slow drains, frequent backups, toilet bowl gurgling, damp spots on the surface even when it hasn't rained.
  • Why Monticello-specific: many yards have established trees close to leach fields, and root intrusion is a common issue as systems age.
  • What to do:
    1. Have a camera inspection of the lines to verify root intrusion and the integrity of piping.
    2. Prune or manage tree roots or relocate landscaping away from the drain field if possible.
    3. If intrusion is extensive, discuss pipe replacement or rerouting the field with a licensed pro.

Resources:

Aging systems and maintenance gaps

Homes built decades ago may have outdated components, corroded tanks, or leach fields that no longer meet current performance standards. Without regular pumping and inspection, solids accumulate and the system begins to fail.

  • Symptoms: frequent backups, indoor sewage odors, standing water near the distribution box, or no drainage in the yard after pumping.
  • Why Monticello-specific: some early installations used older tank designs or materials that wear out, and prolonged time between inspections is more common in older neighborhoods.
  • What to do:
    1. Check the last pumping date and service history; most systems benefit from a professional pump every 3–5 years (varies by tank size and usage).
    2. Schedule a full system evaluation with a licensed septic contractor and consider upgrading to more durable components if needed.
    3. Implement a maintenance plan (pump-out schedule, filter checks, and careful waste disposal).

Resources:

Seasonal water use and irrigation spikes

Wet winters and spring thaws, followed by summer irrigation, can overload a drain field that's already marginal. In Monticello, outdoor water use and lawn irrigation can push the system beyond its designed capacity.

  • Symptoms: slower drainage during summer, increased odor or damp areas around the field after watering.
  • Why Monticello-specific: seasonal patterns and occasional droughts followed by bursts of irrigation can stress older fields.
  • What to do:
    1. Stagger irrigation times and avoid watering during unusually wet conditions.
    2. Fix leaks and install water-saving fixtures to reduce daily household load.
    3. If overload is ongoing, consider a field upgrade or dosing system to spread effluent more evenly.

Resources:

Septic Inspection, Permits & Local Oversight

Local oversight and regulating bodies

  • In Monticello, septic work is overseen at both the city and county level, plus state guidelines. The City of Monticello Building/Zoning department is typically the first contact for permits and inspections within city limits. Wright County Environmental Health often handles on-site wastewater system permits and inspections for areas outside municipal control or when the county is the local agent for state OWTS rules. The Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Health (MDH) provide overarching standards and guidance for safe, compliant systems. To confirm who administers your permit and schedule inspections, start with Monticello City Hall and ask about the current process for OWTS work in your exact neighborhood.
  • If your property sits outside the city limits or in a county-designated area, Wright County Environmental Health is usually the go-to point of contact for permit review, soil testing requirements, and inspections. They coordinate with licensed septic installers and maintain records of installations, upgrades, and replacements.
  • For state-level standards, you can review MPCA's On-site Wastewater Treatment Systems information and MDH's OWTS resources. These bodies set the technical requirements for sizing, setback, groundwater protection, maintenance, and long-term performance.

Resources:

  • City of Monticello:
  • Minnesota Department of Health On-site Wastewater Systems:

Permits you may need

  • Building permit for installation, modification, or abandonment of an on-site wastewater system. In Monticello, this usually comes through the city's Building/Zoning office if you're inside city boundaries, or through Wright County Environmental Health if you're outside the city or if the county handles OWTS permits.
  • OWTS permit (state and local). The permit ensures the system design meets current standards and is installed by a licensed contractor. Expect review of soil tests, design plans, and site-specific factors.
  • Plan review and approval. You'll typically submit a site plan (property lines, setbacks, soil boring/log data), a system design drawing, and installer credentials. Plans must align with Minn. OWTS rules and local codes.
  • Soil and percolation testing requirements. Depending on lot size, slope, and soil conditions, you may need percolation rate tests or soil borings as part of the design submission.

The inspection process (step-by-step)

  1. Identify the permitting authority. Contact Monticello City Hall or Wright County Environmental Health to confirm whether city or county permits are required for your property.
  2. Gather required documents. Property survey or legal description, site plan showing setbacks (house, wells, property lines), proposed system design, soil test results, and contractor/licensed installer information.
  3. Submit plans and pay fees. Turn in the permit application, plans, and required fees to the appropriate agency. You'll receive a permit number and inspection timeline.
  4. Schedule the inspections. Inspections typically occur at multiple stages: prior to backfill (underground components), upon completion of installation, and a final inspection after testing.
  5. Pass the inspections. The inspector checks excavation support, pipe grades, distribution, septic tank integrity, and pump chamber labeling, then verifies the system operates as designed.
  6. Obtain and keep the certificate. After final approval, you'll receive a certificate of compliance or final permit record. Keep a copy for future property transactions and maintenance planning.

What to have ready and best practices

  • Hire a licensed septic installer familiar with Minnesota and local Monticello requirements.
  • Have access to the site on inspection days; clear obstacles and mark potential points of contact for the inspector.
  • Keep all permit numbers, plan drawings, and inspection reports organized with your property records.
  • Schedule regular maintenance (pumping, filter checks) as recommended by the design to avoid future permit complications.

Helpful resources

  • Monticello City Hall / Building & Zoning: official guidance on city permits and inspection scheduling.
  • Wright County Environmental Health: permit applications, inspection scheduling, and OWTS guidance.
  • MPCA On-site Wastewater Treatment Systems: state standards, design criteria, and compliance information.
  • Minnesota Department of Health OWTS: state resources, maintenance tips, and homeowner guidance.

Septic Maintenance for Homes in Monticello

Monticello climate and soil context

Monticello homeowners contend with cold winters, spring thaws, and a variable soil profile. The groundwater table can rise after snowmelt, and frost can influence maintenance windows. Plan yard work and drainage around the seasons, and avoid heavy activity over the drainfield. Knowing your site helps you spot problems early.

Regular inspections and pumping

  • Schedule a visual inspection at least once a year, paying attention to surface wetlands, odor, suface pooling, or lush growth over the drainfield.
  • Pump the septic tank every 3–5 years for typical households; more frequent pumping may be needed if you have a garbage disposal, high water use, or a large family.
  • After pumping, have the pumper check tank baffles, measure liquid depth, inspect for cracks, and verify the effluent screen (if installed).
  • Keep a simple maintenance log: date of pumping, tank size, and any repairs or recommendations.

Protect the drainfield

  • Avoid heavy equipment, vehicles, or foot traffic on or directly over the drainfield to prevent soil compaction.
  • Plant only shallow-rooted grasses over the drainfield; keep trees and shrubs away to minimize root intrusion.
  • Do not connect sump pumps, roof drains, or surface water downspouts to the septic system.
  • Use water efficiently: run full loads, spread laundry over several days, and fix leaks promptly to reduce wastewater volume.

Seasonal considerations for Monticello

  • In spring, watch for standing water near the drainfield; do not drive over a flooded area until it dries.
  • In winter, keep vent pipes clear of snow; avoid piling heavy snow over the drainfield to prevent issues with drainage and access.
  • If you have an inline or effluent filter, clean or replace per manufacturer guidance and keep the filter housing intact.

Troubleshooting and when to call an expert

  • Common warning signs: slow drains, gurgling pipes, sewage smells inside the home, wet spots or bright, lush growth over the drainfield, or water pooling in the drainfield area.
  • If you notice any symptoms, contact a licensed septic professional in the Monticello area promptly; avoid DIY repairs beyond basic cleaning.
  • Do not mix household chemicals, solvents, paints, pesticides, or oil into the system, as they can disrupt beneficial bacteria and damage the tank or leach field.

Local resources and relevant regulations

  • MPCA: Septic systems and wastewater management—Septic systems:
  • Monticello city information:

Cost Expectations for Septic Services in Monticello

Septic Tank Pumping

  • What it includes: removing settled sludge and floating scum, inspecting accessible baffles and the tank interior, and checking the operating condition of any installed effluent filters.
  • Monticello-specific notes: winter access can affect scheduling and may incur a small surcharge if roads are snowy or driveways need clearing.
  • Typical cost in Monticello: roughly $275–$475 for a standard 1,000-gallon tank; larger tanks (1,250–1,500 gallons) commonly run $350–$600. Additional disposal or haul charges may apply if the pump truck must travel farther or if special handling is required.
  • Scheduling guidance: most homes with average family usage pump every 3–5 years; higher wastewater generation or long intervals between pumping can shorten the interval.
  • How to prep: locate the tank, ensure clear access (driveway cleared, exterior hatch accessible), and remove pets or vehicles from the area.
  • Official resources: Minnesota Department of Health OWTS guidance (onsite wastewater):

Septic System Inspections and Certifications (including Real Estate Transfers)

  • What it includes: visual inspection of the tank, baffles, outlets, and any visible piping; check for leaks and signs of failure; may include dye tests or camera review of accessible lines; written report with recommendations.
  • Monticello-specific notes: a real estate transfer inspection is common in Minnesota and may be required or strongly advised during a home sale in Monticello or Wright County; costs vary by scope.
  • Typical cost in Monticello: basic inspection around $200–$400; full transfer/new-home evaluation or dye testing may push $400–$700.
  • Steps to take: hire a licensed OWTS inspector, obtain the written report, and plan any needed repairs before closing or occupancy.
  • Official resources: MDH OWTS program:

Drainfield Repair or Replacement

  • What it includes: fixing broken lines, replacing cracked pipes, restoring or enlarging the absorption area, and possibly upgrading from a failing drainfield to a new design.
  • Monticello-specific notes: replacement projects may require permits and compliance checks with Wright County or Monticello; soil and access conditions strongly impact cost.
  • Typical cost in Monticello: repair often $5,000–$15,000; full drainfield replacement commonly $8,000–$25,000 or more, depending on size, depth, and site constraints.
  • Steps to plan: obtain multiple bids, confirm warranty terms, and verify permit requirements early.
  • Official resources: MDH OWTS program: https://www.health.state.mn.us/communities/environment/wastewater/onsite/index.html

New System Installation / System Design

  • What it includes: site evaluation, soil testing, system design, permit coordination, trench or mound layout, and installation by licensed pros.
  • Monticello-specific notes: local permits and design standards must align with state guidelines and Wright County or city requirements; costs reflect soil, lot size, and system type.
  • Typical cost in Monticello: installed systems typically run $12,000–$30,000+, with higher costs for complex soils or challenging access.
  • Steps to execute: hire a designer, secure permits, and schedule installation with a licensed contractor.
  • Official resources: MDH OWTS program: https://www.health.state.mn.us/communities/environment/wastewater/onsite/index.html

Maintenance Plans and Preventive Care

  • What it includes: scheduled pumping, filter or baffle inspections, alarm checks, and practical guidance to extend system life.
  • Monticello notes: a proactive maintenance plan can prevent costly repairs and reduce surprise failures, especially in aging homes.
  • Typical cost: annual maintenance plans generally range from $250–$450, depending on services included and pump frequency.
  • Best practice steps: set reminders, follow manufacturer and local guidelines, and address issues promptly.
  • Official resources: MDH safe-operations guidance: https://www.health.state.mn.us/communities/environment/wastewater/onsite/index.html

Minor Repairs and Component Replacements (Valves, Pumps, Alarms)

  • What it includes: replacing worn components like risers, baffles, float switches, lift pumps, or alarms without a full drainfield rebuild.
  • Monticello cost range: typically $150–$1,500 depending on part availability, access, and labor.
  • When to book: for unusual odors, slow drains, or alarm trips, contact a licensed OWTS tech promptly.
  • Official resources: MDH OWTS program: https://www.health.state.mn.us/communities/environment/wastewater/onsite/index.html

Septic Tank Dye Test

Official resources