Well and Septic Basics on Cottage Grove’s Edge

Looking at a home on the edge of Cottage Grove and seeing “private well” and “septic” on the listing? You are not alone. Many acreage and fringe properties here rely on their own water and wastewater systems, and that can raise smart questions during a sale. This guide explains what to check, which tests and inspections matter, and how local rules affect your closing. Let’s dive in.

Why wells and septic matter locally

Cottage Grove allows private wells and on-site sewage in certain areas, and some parcels are expected to connect to public utilities when they become available. If a home has access to city sewer and a private system fails, connection may be required by the city. You can review local sewer and connection information on the city’s sewer services page.

Washington County administers the area’s septic program, including permits, inspections, and records. If you are buying or selling, start with the county’s Subsurface Sewage Treatment Systems hub for policies, forms, and record lookups on the Washington County SSTS page.

Private wells: basics and testing

What to look for on site

Most private wells around Cottage Grove are drilled wells, with a visible wellhead and cap, a steel or PVC casing that should extend at least a foot above ground, and indoor components like a pressure tank and pump. You may also see water treatment devices such as softeners or filters. Confirm that the well cap is tight, the casing is intact, and the area around the well stays clean and graded to shed water.

What to test and when

MDH recommends you test annually for total coliform bacteria and nitrate, and test at least once for arsenic, lead, and manganese. Test again after servicing, flooding, or plumbing changes. See MDH’s guidance on what to test and how to use accredited labs on the private well testing page.

PFAS is a known East Metro issue due to historic disposal sites. If a property is near investigation areas or you want added peace of mind, review current information and consider PFAS testing. You can learn more on the MPCA’s overview of the East Metro PFAS contamination.

Records and unused wells

Ask the seller for the well disclosure certificate and any past water test results. You can also look up well construction and sealing records using the Minnesota Well Index (MWI) and review MDH guidance on well disclosures at property transfer. Unused wells must be legally sealed by a licensed contractor unless the owner holds a maintenance permit. Washington County offers cost-share help for sealing; see the county’s page on abandoned wells.

Septic systems: how they work and how to care for them

How a system works

A typical system includes a septic tank that holds and separates wastewater, plus a soil treatment area that disperses treated effluent. The exact design depends on soil conditions and local requirements. Your inspection report will identify the type and condition of the system.

Maintenance and pumping

Plan for a licensed maintainer to evaluate your tank at least every three years and pump as needed. Many households pump every 3 to 5 years, depending on tank size and water use. Ask about risers, baffles, and effluent filters, and keep all service reports. For homeowner guidance, review MPCA’s tips on septic service and maintenance.

Signs of trouble

Watch for slow drains, sewage odors in the yard, wet or spongy ground above the drainfield, very lush grass over the leach area, or abnormal snowmelt patterns. If you see any of these signs, schedule an inspection and address issues promptly.

At closing: inspections and paperwork

Sellers: plan for a compliance inspection

Washington County requires a septic compliance inspection when you sell, unless a valid certificate is already on file. Existing-system certificates are typically valid for three years. Start early and review the county’s requirements on the Washington County SSTS page.

A key Minnesota rule change means the tank usually must be pumped so the inspector can assess it properly. An empty-tank assessment completed within the last three years may be used in some cases. Read a summary of the update from Minnesota Realtors on the SSTS rule change.

Also gather your well disclosure form, any well records, and recent water tests. If a well is not in use, provide sealing documentation or a maintenance permit.

Buyers: request the right documents

Before you close, ask for the well disclosure certificate, the well log or MDH record if available, and recent water test results. Request the septic compliance certificate and maintenance or pump-out records. If documents are missing or expired, plan for your own water testing and a new compliance inspection.

Help paying for fixes

System costs vary by site, design, and local rules. If your well needs sealing or your septic needs repair or replacement, Washington County offers low-interest loans and grants with eligibility requirements and limited funds. Check availability directly with the county’s SSTS and well programs.

Quick checklist for buyers and sellers

Sellers

• Order the septic compliance inspection if the certificate on file is not current.
• Schedule tank pumping in time for inspection if required.
• Compile well disclosure, well records, and recent water tests.
• Gather septic pump-out and maintenance records.

Buyers

• Ask for the well disclosure, well log, recent water tests, and the septic compliance certificate.
• Independently test the well for bacteria and nitrate, and at least once for arsenic, lead, and manganese.
• Consider PFAS testing if the property is near East Metro investigation areas.
• Review county and MDH records before you waive contingencies.

Who to call for local help

• Washington County Public Health & Environment, SSTS and well programs: 651-430-6655
• City of Cottage Grove Public Works, sewer and water questions: 651-458-2808
• Minnesota Department of Health, Well Management: see MWI and well disclosure pages for contacts
• MPCA, SSTS licensing and guidance: use agency pages to find licensed inspectors and maintainers

Ready to move forward with confidence on a Cottage Grove acreage or edge-of-town property? The Cooking Real Estate Team will guide you through testing, inspections, and negotiations so you can close smoothly.

FAQs

Do Minnesota sellers have to inspect a private well at sale?

• There is no statewide well inspection requirement at transfer, but sellers must disclose well status and records; buyers commonly order independent testing and inspections.

Is a septic inspection required when selling in Cottage Grove, Washington County?

• Washington County requires a septic compliance inspection at sale unless a valid compliance certificate is already on file, typically valid for three years on existing systems.

How often should I pump my septic tank in Minnesota?

• Have a licensed professional assess the tank at least every three years and pump as needed; many households pump every 3 to 5 years depending on usage and tank size.

What water tests should I run on a private well?

• Test annually for total coliform bacteria and nitrate, and at least once for arsenic, lead, and manganese; consider PFAS testing if local investigations indicate a risk.