Septic installers: the completed-operations tail you carry for years

The honest answer is that a septic installer’s real exposure starts the day the job ends. The tank is in, the county inspector signed the card, the homeowner paid. Then the system sits in the ground for decades, and if it fails in year four, the claim doesn’t care that you’ve had three policy renewals since. It comes looking for the policy that was in force the day the drain field quit. That’s the completed-operations tail, and it’s the whole reason a septic installer’s policy has to be built differently from a grader’s. Here’s how the tail works, which form keeps working after you cancel, where the pollution exclusion swallows the claim, and what the county wants before it lets you dig.

What “completed operations” means on your job

General liability has two halves. Premises and operations covers what happens while you’re working: the mid-size excavator finds the gas service, a laborer’s bucket swing takes out the homeowner’s fence. Products and completed operations covers what your finished work does to people and property after you’ve left.

For most excavation trades, ongoing operations is where the claims are. For a septic installer it’s reversed. Your finished work is a wastewater system buried in somebody’s yard, and the ways it fails are slow:

• A drain field in bentonite near Bailey stops taking water in the third spring. Effluent surfaces in the lawn. The homeowner’s kids play in it.
• A tank set on a high-water-table lot outside Fairplay floats after a wet year, cracks the inlet line, and sends sewage toward the neighbor’s well.
• A distribution box settles because the bedding wasn’t compacted over saturated clay, and one lateral takes the whole load until it fails.

Each of those is a completed-operations claim. Under most standard general liability forms it’s included, with its own aggregate limit, and it’s the line a builder or a lender wants to see on the certificate. It’s also the line that gets removed, sublimited, or excluded on cheaper forms, so read yours.

Occurrence vs claims-made: the form that keeps working

This is the decision that matters most for a trade with a long tail, and most installers have never been asked about it.

Occurrence forms respond to damage that happens during the policy period, no matter when the claim is made. A system you installed in 2022 under an occurrence policy fails in 2026. The policy that was in force when the damage occurred is the one that responds, even if you switched carriers twice since, even if you retired. That’s why we tell every installer to keep every expired policy in a drawer. They’re not dead paper. They’re the coverage for the systems you put in that year.

Claims-made forms respond only to claims made while the policy is in force, and often only for work after a retroactive date. Cancel a claims-made policy and, without tail coverage (an extended reporting period), the claims that come in next year have no policy at all. Tail coverage exists, and it costs real money, and you buy it at the worst possible time: when you’re closing the business.

Most contractor GL in Colorado is written on an occurrence form. Not all. Some markets that write septic and pollution exposure use claims-made, and it’s on the dec page in small type. The policy review looks for it first. If you’re on claims-made and didn’t know, that’s the most important thing you’ll learn this year.

Whichever form you’re on, when the damage “occurred” is itself an argument. A drain field that fails slowly may have started failing under one policy year and surfaced under another. Carriers have language for this and it isn’t consistent. That’s a real unknown, and one to raise with your agent before the claim rather than during it.

The exclusions that follow the tail

Completed operations coverage pays for damage your work causes. It typically does not pay for the work itself. Two exclusions do most of the cutting.

Your work. Under most standard forms, the cost to dig up and rebuild the failed drain field is excluded as your own work. That’s your warranty. What is commonly covered is the resulting damage: the neighbor’s contaminated well, the homeowner’s basement, the landscaping the backhoe has to go through to fix it. The line between “your work” and “resulting damage” is where most completed-operations claims get argued, and it’s why the form language and the adjuster’s read matter more than the limit.

Pollution. This is the one that swallows septic claims. Sewage in a creek, effluent in a well, a plume reaching the neighbor’s spring: under most standard GL forms that’s a pollution claim, and the GL pollution exclusion is broad. The cleanup, the well replacement, the state’s involvement can all fall outside the GL entirely. Pollution liability, written with completed operations included, is how installers close that gap. Without it, the worst version of your worst claim is uninsured. The policy language controls, so send us the GL form and we’ll show you where the exclusion sits.

The XCU article covers the other three letters that can fall off a cheap GL form. For a septic installer, the tank hole is the underground exposure, and the excavator opening it is the same gas line risk every other dig carries.

The county license and the certificate

Colorado runs septic at the county level, and the county is who lets you dig.

The regulatory term is “systems contractor,” not installer, and the licensing itself is local. Two examples from counties where we see a lot of septic work:

Most county programs want a certificate of insurance with the application or the renewal. What they ask for varies: some want GL at a stated limit, some want the county named as certificate holder, some just want proof it exists. Call the public health agency for the county where the job is, not the state, and ask what the certificate has to say before you apply. The septic installer page has the counties we see most and the Park County page has our own county’s setup.

Where an engineered system is involved, the designer sometimes wants to be named as additional insured on your GL for completed operations. That’s the same request a GC makes on a commercial job, for the same reason: if the system fails, everyone with a name on the permit gets sued, and your policy is the one they want defending them. The subcontractor article has the other side of that request.

Sizing the policy for the tail

Here’s what we tell every installer who asks. Your GL limit has to fit the worst completed-operations claim you can picture, not the job you’re on. A well replacement, a family’s temporary housing, and a neighbor’s attorney add up fast, and the products-completed operations aggregate is its own number that has to hold all of it for the year. If you install thirty systems a year, you have thirty tails running at once.

Then the pollution policy, sized to a cleanup, with completed operations and a term long enough to matter. Then the contractor’s equipment for the machine in the hole, scheduled at a number that replaces it. Then comp at the first laborer, and commercial auto for the truck and the tank trailer.

What we don’t control

Whether the county program in a given county wants a certificate, and what it has to say. Whether the carrier writes your GL on occurrence or claims-made this year. How an adjuster draws the line between “your work” and resulting damage on a failed drain field, which is the argument most of these claims turn into. And the tail itself: Colorado limits how long after completion a construction claim can be brought, with exceptions, and the number is a question for your attorney. What we can do is build the policy with completed operations on it, work on closing the pollution gap, and make sure the old policies are somewhere you can find them.

Where to go from here

The septic installer page has the full coverage stack, the exposures by county, and the FAQs we hear most from installers. If you want to know whether your GL is occurrence or claims-made, and whether completed operations is actually on it, send us the dec page. The excavation insurance hub covers where septic fits with the rest of the dirt trades, and the retaining wall article has the same completed-operations problem on the landscaping side.

Serving businesses located in Colorado. Coverage is determined by the policy language and the carrier.