What Is a Spill Delineation? A How-To Guide for Colorado Homeowners

Our client in Arvada recently had a major house fire — one of those everything-smells-like-smoke-for-weeks kinds of situations. Unfortunately, the home had textured drywall containing asbestos, which turned cleanup into more of a saga than a weekend project.

When we told him the next step was a spill delineation, he gave us that classic pause. You know the one. The “I’ve spent enough already, do I really need another test?” pause.

We get it. Spill delineations aren’t exactly the kind of thing you frame on your wall, and they can get expensive really quick. But when he called around to check with the abatement company, the State, and even his insurance adjuster, they all said the same thing:

“You can’t move forward without a spill delineation.”

So, he called us back a few days later and said, “Sooo… about that delineation.” We went right to work!

A spill delineation is the asbestos world’s version of CSI — complete with sampling, lab results, and the occasional “oh no, it went that far?” moment. Here’s what it is, why you can’t skip it, and what actually happens when the State, your abatement company, and your insurance adjuster all tell you the same thing: “You need a delineation.”

What Is a Spill Delineation, Anyway?

In plain English: a spill delineation is the process of figuring out how far the asbestos went after a major disturbance — like a fire, flood, or ceiling collapse.

Think of it like drawing the crime scene chalk line around your asbestos spill. The goal? To “delineate,” or mark, the boundaries of where contamination ends so cleanup can begin.

A Certified Air Monitoring Specialist (AMS) comes out to collect wipe and/or air samples from around the property. These are sent to a certified lab, where they’re analyzed to see where asbestos fibers landed.

The results are used to create a roadmap for everyone — narrowing down the cleanup area so they don’t have to treat your entire home like a hazmat zone.

There's different types of spills too. To find out the difference, check out our Minor vs. Major Spill blog for how the State decides which one you’ve got.

Spill Delineation: The CSI Episode of Asbestos

This is the part in the asbestos story where science steps in with a magnifying glass.

Your Air Monitoring Specialist becomes a little bit of a detective — gathering evidence (samples) and analyzing the “scene.” Every wipe and air sample is like a clue, showing how far those invisible asbestos fibers traveled.

Without those clues, the abatement team would be guessing — and that’s the environmental version of cleaning your whole house blindfolded.

Why the State of Colorado Cares (and So Should You)

Colorado’s Department of Public Health and Environment (CDPHE) is serious about asbestos safety. Under Regulation 8, Part B, if a major spill occurs, you MUST have a spill delineation performed by a certified Air Monitoring Specialist before cleanup and for the permit to be approved.

That’s not bureaucracy — that’s liability prevention.

The State wants to make sure everyone knows exactly where asbestos is (and isn’t). Without delineation results, no one can issue permits, no abatement can begin, and your insurance company can’t process the claim.

It’s the environmental equivalent of trying to bake cookies without preheating the oven — you can’t skip the setup.

Let's Breakdown Interior vs. Exterior Spill Delineations

Interior Spill Delineation

This is where things get personal — literally inside your walls, floors, and furniture.

An interior delineation looks for asbestos fibers that spread through the home’s interior. The AMS takes wipe samples from cleaned surfaces to determine the extent of contamination. If the spill happened less than 72 hours, then an AMS can do air samples.

If the entire inside of your home is so bad that it is fully classified as a interior major spill, then samples may not be needed — because, well, everything’s contaminated anyway. This happens with major fire losses.

Only an AMS can make that call though. But when there’s even a chance that some areas are unaffected, interior delineation helps narrow the scope. If the spill happened in your kitchen upstairs, then does the basement really need to be cleaned? Probably not...that is why a spill delineation is a life saver!

It’s like saying, “Hey, maybe we don’t need to throw out little Bobby Joe's stuff animals in his room that was more than 20 feet away from where the spill happened.” Little Bobby Joe probably will appreciate this added step.

Exterior Spill Delineation

Even if the inside is toast, an exterior delineation will ALWAYS be required, no matter what.

The State wants to make sure no asbestos fibers made it outside — because if dust or debris ends up in your yard, dumpster, driveway, or garden, it can spread beyond your property line. This happens a lot in Colorado when it's super windy or raining.

The U.S. Environmental Protection Agency (EPA) guidelines also require this to ensure public safety. So if you thought you could skip it because your grass “looks fine,” think again. Your lawn might be innocent, but the State still wants proof.

The good news is that in most cases, wipe or air samples are not needed to complete an exterior spill delineation. This can usually be done by just a visual inspection or by collecting "bulk" samples of the material found outside. (FYI...bulk samples are much cheaper than wipe or air samples lab costs wise).

If you have questions on whether you need an interior or an exterior spill delineation, give us a call! We're happy to chat about it.

What Actually Happens During a Spill Delineation

Here’s the play-by-play:

1. Visual Inspection: The AMS walks through your property, looking for visible dust, debris, or suspect materials.

2. Sampling Strategy: They choose where to take wipe or air samples — high-touch surfaces, normally cleaned flat areas, or rooms adjacent to the spill.

3. Sample Collection: They collect samples carefully, bag them, label them, and send them to a certified lab.

4. Lab Analysis: The lab analyzes each sample under a microscope to detect asbestos fibers.

5. Results and Report: The AMS compiles all the data into a Spill Delineation Report, which outlines where asbestos was detected and where it wasn’t. A good AMS walks you through the results and areas impacted. A SUPER good AMS and team makes it as least scary as possible and gives you next steps and options (cough cough...that's what we do).

This report is your golden ticket — it tells the State, the abatement company, and your insurance provider exactly what needs to happen next.

Why It Costs So Much (And Why It’s Worth Every Penny)

We’ll be honest — a spill delineation isn’t cheap. But there’s a reason it’s pricey. Let’s break it down.

• Lab Fees: Each sample gets analyzed under a microscope by a certified professional to determine specific fibers counts and asbestos concentration.

  • Lab costs can range from $150 to $300 per wipe sample. Unfortunately, the number of samples needed is based on the layout of the home and the number of areas the AMS is trying to investigate. We at Elevation Environmental do everything within our power to keep the samples count down as much as possible, but sometimes, it's unavoidable.

• Reporting & Compliance: The AMS has to meet strict State and insurance documentation requirements.

  • There is A LOT of back and forth between the AMS, the State and the abatement company review the scope of work and the report. Not all of it is cut and dry. Some cases are more complicated and need more communication to get to a resolution.

• Multiple Trips: Sometimes the State requires additional samples to be collected or the abatement company wants to meet the AMS on-site to discuss the property in-person.

• Licensing: Only certified specialists can do this work — and maintaining that certification is pricey in the state of Colorado.

  
  

Depending on the size of the property and number of samples, costs can range from a few hundred to a few thousand dollars. But that report? It’s what keeps your cleanup legal, safe, and covered by insurance. It also could save you even more on the abatement clean-up side as well.

How Long Does It Take?

Usually, the delineation visit is done in a few hours. The lab results take about 1–3 business days, depending on how many samples were taken.

Once the results are in and the report is written, the abatement company can move forward confidently—armed with data instead of guesswork.

Who Gets the Report?

You won’t be the only one with homework after this. Copies of your delineation report go to:

• The State (CDPHE) – to approve your abatement permit

• The Abatement Company – to map out cleanup zones

• Your Insurance Company – to verify scope and coverage

• You, the Property Owner– because you deserve to know what’s happening in your own property. Plus, that is a requirement under CDPHE Regulation 8.

This part is our favorite because it's getting everyone on the same page and moving forward to help you!

Why You Can’t Skip the Science (Even if You Want To)

We know it’s tempting to save money and move straight to cleanup. But skipping delineation is like guessing where your dog buried the remote — you’ll dig up the wrong spot and make a bigger mess.

Not only that, but you could be paying more on the clean-up then really needed.

Without it, no one knows how far the contamination spread. And if cleanup is incomplete, the State can issue fines, insurance payments can stall, and your abatement company will be stuck in regulatory limbo.

Bottom line: delineation isn’t just red tape — it’s your roadmap to getting your home back safely, cost effectively and legally.

We'll leave you with this...

Here's the thing, sometimes when someone calls something a major spill, it's not. A lot of building inspectors can get spill happy without doing everything possible to avoid using that term (i.e. Drywall Composite, Point Count etc).

Here at Elevation Environmental Services, we always want to make every effort first to make sure a spill is actually spill, because we know how expensive it can get. We have turned away spill delineation requests because the initial inspector didn't do the inspection right or missed a step that could be a game changer.

So if you have a report that says you have a major spill and you need it triple checked, let us know! We're happy to advise. Free of charge!

And if you’re dealing with a confirmed major spill in Denver, Arvada, Aurora, Lakewood, Centennial or beyond, our certified Air Monitoring Specialists can handle your delineation quickly and professionally — with a little humor to make it less stressful.

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