Jefferson County recently updated its Onsite Wastewater Treatment System (OWTS) regulations.

For most homeowners, the new rules will not trigger immediate excavation or emergency work unless a serious safety issue, system failure, or permit-related requirement is identified during an inspection, evaluation, or permitting process.

But if you’re selling a home, repairing a system, replacing components, or planning future improvements, today’s standards may look different than what was acceptable when your system was originally installed.

Jefferson County’s updated regulations align with Colorado Regulation 43, which governs onsite wastewater treatment systems statewide.

Here are the changes homeowners should pay attention to.

1. Older Septic Tank Types Are Receiving More Attention

One of the biggest practical changes for mountain homeowners:

Jefferson County’s public guidance notes that older wood, metal, and cinderblock septic tanks are no longer allowed, and replacement may be required when identified during permitted work or a use permit review.

If one of these tanks is discovered during a permitted inspection, repair, replacement, or transfer-related use permit review, Jefferson County may require replacement with an approved septic tank.

County staff and inspectors are placing greater focus on identifying older or non-standard tank materials during regulated work and transfer processes.

Why this matters:

Many homeowners do not actually know what type of tank they have.

We regularly see situations where records are incomplete, or assumptions don’t match what’s underground.

If your home was built decades ago and your septic history is unclear, finding out now is usually cheaper than discovering it during a closing timeline.

2. Modern Access and Protection Standards Are Becoming More Common

Current standards place greater emphasis on accessibility, serviceability, and safe access.

For systems being installed, replaced, upgraded, or reviewed through permitting and inspection processes, homeowners may see more focus on:

• Watertight access risers
• Secure, structurally sound lids designed to help prevent accidental or unauthorized access
• Access configured for easier inspection and pumping, often with risers extended to or near finished grade
• Child-safety-focused lid designs or secondary restraint features intended to reduce accidental access to tank openings
• Effluent filters are intended to reduce solids reaching the soil treatment area and support long-term system performance

Why homeowners should care:

These types of components are generally intended to improve safety, simplify maintenance, and help protect long-term system performance.

This does not automatically mean every existing buried lid or older tank must immediately be excavated or retrofitted.

But when projects trigger review, expect current standards to become part of the conversation.

3. Property Sales May Create New Upgrade Conversations

This may be the biggest practical change for homeowners.

Jefferson County notes that some septic systems may now require enhancements before a property can be sold or transferred.

What that can look like in practice:

A homeowner prepares to sell.

Before closing, the seller initiates the required use permit process, including the inspection requirements established by the county.

The review identifies:

• obsolete tank materials
• inaccessible components
• deferred maintenance
• missing records
• conditions requiring correction before approval

Now the seller is solving septic issues under a contract deadline.

That can create:

• emergency pumping
• excavation
• repair estimates
• permit coordination
• delayed closing timelines

The better move:

If you expect to sell within the next 12–24 months, consider evaluating the system before listing.

That gives you time to understand whether the tank and major components meet current expectations and plan any needed work on your own schedule.

4. New Systems and Repairs Are Being Held to Updated Standards

Jefferson County’s updated regulations also reflect broader changes tied to state requirements.

Depending on the project, homeowners may encounter:

• updated design expectations
• treatment requirements based on site conditions
• revised repair approaches
• newer component standards

If you’re replacing a tank, rebuilding part of a system, or pulling permits, assume current standards — not original installation standards — will drive decisions.

In many cases, that means upgrades to tank materials, access components (such as risers and lids), and overall system design when the system is altered under permit.

What Should Homeowners Do Right Now?

You do not need to panic.

But this is a good time to act if:

✓ You do not know what type of tank you have

✓ Your system is more than 15–20 years old

✓ You expect to sell in the next few years

✓ You’re planning repairs or improvements

✓ You’ve never had the system inspected

If you’re not sure what’s in the ground, we can help identify your system and help you understand what applies before a permit, inspection, or transaction creates a deadline.

South Platte Services has been serving the foothills and working on these mountain septic systems since 1972.