The Underground Storage Tank (UST) Closure Report is the document package a tank owner or operator submits to their local regulator to prove a buried fuel or chemical tank was emptied, cleaned, and shut down the right way. In California, you file it through your local Certified Unified Program Agency (CUPA) and update the state’s online system, the California Environmental Reporting System (CERS), within 30 days of the closure, as required under CCR, Title 23, Section 2672 and Health and Safety Code Section 25298.
Getting this report wrong is not a small paperwork slip. A missing soil sample, a blank signature box, or a late filing can leave your tank legally “open” in the eyes of the state, block a property sale, and expose you to fines that reach $5,000 per tank per day under California law. With more than 30,000 active USTs still regulated across the state and a hard December 31, 2025 deadline that forced thousands of single-walled tanks out of service, the volume of closure filings has surged, and so have rejections for incomplete reports.
Here is what you will learn in this guide:
- 🛢️ What the UST Closure Report is, who must file it, and the exact agency that receives it
- 📋 The full pre-filing checklist of documents, IDs, and sample results you need before you start
- ✍️ A line-by-line walkthrough of every field on the closure application and the CERS submittal
- 👤 Three real filer scenarios that show what to enter from start to finish
- ⚠️ The most common mistakes that get reports rejected and how to avoid every one
What the Form Is and Who Must File It
The UST Closure Report is not a single one-page form. It is a package built around three parts: a UST Closure/Removal Permit Application filed with your local CUPA, the supporting closure documentation (soil samples, disposal records, and a closure report narrative), and the CERS submittal that updates the tank’s status in the statewide database. Together these prove the tank is permanently or temporarily out of service and that the soil beneath it is clean.
The owner of the UST is legally responsible for filing, even when a contractor does the physical work. This is spelled out in the Orange County removal guidelines, which apply the permanent closure rules of the California Code of Regulations to the owner. In practice, three groups touch the report: the tank owner or operator (a gas station, fleet yard, or property owner), the licensed tank contractor who removes or fills the tank, and the environmental consultant who collects and interprets the soil samples.
You must file if you are permanently closing a tank by removal, closing it in place by filling it with an inert solid, or temporarily taking it out of service. The agency that receives your filing is your local CUPA or Unified Program Agency (UPA), which in San Francisco is the San Francisco Department of Public Health, and in Los Angeles County is the LA County Fire Department or Public Works. The statewide oversight body is the State Water Resources Control Board, which audits CUPA closure files for completeness.
A common misconception is that closing the tank physically ends your duties. It does not. The state still treats the tank as regulated until the CERS record shows a permanent closure date and the CUPA issues a closure letter, so skipping the paperwork keeps you on the hook for annual fees and inspections.
Before You Start: Documents and Information You Need
Closure filings get rejected more for missing attachments than for wrong answers in boxes. Gather every item below before you open the application, because the CUPA reviews the package as a whole and a single gap can reset the clock on your 30-day deadline.
- Facility ID number — your unique CERS facility identifier; without it the CUPA cannot match your filing to the right site.
- Tank ID numbers — the CERS Tank ID for each UST being closed; mixing these up closes the wrong tank in the database.
- Owner and operator legal names and addresses — must match your existing CERS permit, or the submittal will not accept.
- Licensed contractor information — the contractor’s name, license number, and certification, because unpermitted closure work is a violation.
- Closure method decision — removal or closure in place; this drives which permit conditions and samples apply.
- Soil and groundwater sample results — lab analytical reports and chain-of-custody forms, the single most-checked attachment in any closure file.
- Site drawing or plot plan — shows tank locations and sample points, required by most CUPAs for plan check.
- Disposal and manifest records — proof of proper disposal of residual liquids, sludges, and the tank itself.
You should also have your closure plan and permit approval date, a tank tightness or last inventory record, and the original installation date of the tank. If the install date is unknown, the State Water Board CERS instructions tell you to enter 1/1/1900 rather than leave it blank. Missing the disposal manifest is the most damaging gap, because without it the regulator cannot confirm the tank and its contents were handled as hazardous waste, and the file stays open.
Where to Get the Form and How to Access It
There is no single statewide closure form, because California delegates UST oversight to local CUPAs. You get the closure permit application from your local agency’s website, and you complete the CERS submittal through the state portal at cers.calepa.ca.gov. For example, Riverside County publishes a fillable UST Closure Application and Permit, and San Bernardino County uses an Underground Tank Construction/Closure Application.
Start by contacting your CUPA to confirm which version of the closure application is current, since these are revised periodically and an outdated form can be rejected at intake. Always check the revision date printed in the footer of the PDF before you fill it in. Riverside County’s form, for instance, notes that the closure permit is valid for only 90 days from the date of issue, so timing your download to your actual closure schedule matters.
For the CERS side, you need a registered CERS account tied to your facility. If you do not have one, you register as a business user, request access to your facility, and wait for the CUPA to grant it, which can take several days. The official step-by-step for the closure submittal lives on the State Water Board’s CERS closure page, and it is the authoritative source for the exact buttons and fields described below.
Step-by-Step: How to Fill Out the UST Closure Report Line by Line
This walkthrough covers the closure permit application fields first, then the CERS submittal screens. Use the exact field labels printed on your CUPA’s form, because box names differ slightly between counties. Numbers below follow the order fields appear on a typical California closure application and the CERS workflow.
Field 1: Facility Name and Address
This field asks for the legal name and street address of the site where the tank sits. Enter the facility name exactly as it appears on your current UST permit, then the full street address, city, county, and ZIP code in standard format. For example, Bayview Fuel Stop, 1450 Industrial Way, San Francisco, CA 94124 is how a station owner writes it.
A nuance comes up when the business name has changed since the tank was permitted; use the name on the active permit and note the new name separately, because the CUPA matches your filing to its existing record by the permitted name. The most common mistake here is entering a mailing address or corporate headquarters instead of the physical tank site, which sends the closure to the wrong jurisdiction and stalls review. People often believe the address only identifies them, but it actually sets which CUPA has authority, so an error can route your file to an agency that cannot act on it.
Field 2: Facility ID Number
This field asks for the CERS Facility ID, the unique number the state uses to track your site. Copy it directly from your most recent CERS submittal or your annual permit, entering all digits with no spaces. Maria Lopez enters 10-001-456789 from the top of her existing facility record.
If you cannot find the Facility ID, your CUPA can look it up by address, so call before guessing. The most common mistake is transposing two digits, which links your closure to a stranger’s facility and can wrongly mark their tank closed. Many filers think this number is the same as their tank ID, but it is not; the Facility ID covers the whole site while each tank carries its own separate ID.
Field 3: Owner and Operator Information
This field asks who owns the tank and who runs the day-to-day operation, with full legal names, mailing addresses, and phone numbers. Enter the owner first, then the operator if different, using legal entity names such as Lopez Family Holdings LLC rather than a nickname. Include a direct phone and email, because the CUPA contacts this person to schedule the closure inspection.
The edge case is a recent property sale, where the new owner files but the tank is still permitted under the seller; list the current legal owner and attach proof of the transfer. The common mistake is naming the contractor as the owner, which makes the contractor legally responsible for a tank they do not own and confuses liability. A frequent misconception is that owner and operator must be the same; they often differ, and the form has separate lines precisely for that reason.
Field 4: Tank Information and Tank ID
This field asks for details on each tank being closed, including the CERS Tank ID, capacity in gallons, contents, and original install date. List every tank on its own line, entering capacity as a whole number and contents such as Regular Unleaded Gasoline. Carlos Reyes enters Tank ID 001, 10,000 gallons, regular unleaded, installed 06/15/1998.
If the install date is unknown, enter 1/1/1900 as the State Water Board CERS instructions direct, rather than leaving it blank and triggering a system error. The most common mistake is closing the wrong Tank ID when a site has several tanks, which leaves an empty tank shown as active and a full tank shown as closed. People wrongly assume tank capacity is the fuel level at closure; it is the rated capacity of the tank, not how much fuel was left inside.
Field 5: Closure Method (Removal or Closure in Place)
This field asks how you are closing the tank: by physical removal or by closing it in place with an inert fill. Check the single box that matches your method, and never check both, because they carry different inspection and sampling requirements. Janet Okafor checks “UST Permanent Closure on Site” because her tank sits under a load-bearing building and cannot be dug out.
Closure in place is only allowed when removal is not feasible, such as under a structure, and the CUPA must approve that justification first. The most common mistake is selecting removal on the form but then closing in place in the field, which makes your filing contradict the physical work and voids the permit. A widespread misconception is that closure in place is a shortcut; it still requires the tank to be emptied, cleaned, and filled with an inert solid, with soil samples taken just the same.
Field 6: Contractor and Certification Information
This field asks for the licensed contractor performing the closure, including the company name, California contractor license number, and applicable certifications. Enter the license number exactly as issued, with no extra characters, and confirm the license is active. Bayview Fuel Stop lists ABC Tank Services, License No. 845512, ICC-certified.
The nuance is that some counties require a specific tank-removal certification beyond a general contractor license, so verify with your CUPA. The most common mistake is using an unlicensed or expired contractor, which makes the entire closure unpermitted and subject to penalties under the Health and Safety Code. Owners often believe they can self-perform a closure to save money, but California requires a properly licensed and certified contractor for the physical work on a regulated UST.
Field 7: Site Assessment and Soil Sample Results
This field asks for the soil, and sometimes groundwater, sampling results that show whether the tank leaked. Attach the lab analytical report and the chain-of-custody, and summarize the findings, noting whether contamination was detected. David Chen’s consultant attaches lab results showing TPH below detection limits and notes “no release detected.”
The critical edge case is when contamination is found; you must report the unauthorized release to the regulator, which converts a routine closure into a cleanup case under the Leaking UST program. The most common mistake is submitting samples taken from the wrong location or too few sample points, which the CUPA rejects, forcing re-excavation. Filers often assume clean-looking soil means no testing is needed, but sampling is mandatory because petroleum contamination is frequently invisible and odorless at depth.
Field 8: Disposal and Manifest Documentation
This field asks for proof that residual liquids, sludges, and the tank itself were disposed of properly. Attach hazardous waste manifests, disposal receipts, and recycling records, and list the receiving facility. Carlos Reyes attaches a Uniform Hazardous Waste Manifest showing 200 gallons of tank bottoms sent to a permitted facility.
If the tank is recycled rather than landfilled, attach the scrap or reuse documentation as the State Water Board closure list requires. The most common mistake is closing without keeping the manifest, which leaves no proof the waste was handled lawfully and keeps the file open indefinitely. Many owners think the contractor automatically files these for them, but the owner must ensure the documents land in the closure package.
Field 9: Date UST Permanently Closed
This CERS field asks for the exact date the tank was permanently closed, entered as MM/DD/YYYY. On the UST Tank Information/Monitoring Plan page, select either UST Permanent Closure on Site or UST Removal, then type the closure date. Maria Lopez enters 05/12/2026 as her closure date and selects “UST Removal.”
The nuance is that this date starts your 30-day clock to complete the CERS submittal, so enter the true field completion date, not the permit date. The most common mistake is leaving this blank, which the State Water Board flags during audits because Column N of the CERS facility report must contain a date for a valid closure. People wrongly believe the closure date is when they applied for the permit; it is the day the physical closure work finished.
Field 10: Owner Signature and Certification
This field is the signature block where the owner or authorized agent certifies under penalty of perjury that the information is true. Sign and date the form, print your name and title, and ensure the signer has legal authority to bind the owner. Janet Okafor signs as “Managing Member,” dates it 05/20/2026, and prints her name.
The edge case is signing as an agent, such as a consultant; you may sign only if the owner has authorized you in writing, and the CUPA may ask for that authorization. The most common mistake is an unsigned or undated form, which is treated as not filed at all, meaning your deadline keeps running. A dangerous misconception is that the signature is a formality; it is a sworn legal statement, and false information can bring perjury and fraud penalties.
Field 11: CERS Permanent Facility Closure Confirmation
When all tanks at a site are closed, CERS requires a second submittal selecting Permanent Facility Closure as the Type of Action. Per the State Water Board final closure guide, you make a first submittal documenting each tank closed, then a second confirming no regulated USTs remain. David Chen completes both, then changes the UST question on the Facility Information page to “No.”
The nuance is that this two-step process applies even if the business keeps operating with other hazardous materials, because the action is specific to the UST program. The most common mistake is doing only the first submittal and skipping the facility closure confirmation, which leaves the site shown as a UST facility and keeps annual fees billing. Owners often think one CERS submittal handles everything, but both are necessary to fully close the record.
Three Filled-Out Examples Using Real Scenarios
Below are three common closure paths, each following one filer through the key fields from start to finish. These show how the same form handles very different situations.
Scenario 1: Maria Lopez removes two old single-walled tanks at a gas station
| Form Section | What Maria Enters |
|---|---|
| Facility Name and Address | Bayview Fuel Stop, 1450 Industrial Way, San Francisco, CA 94124 |
| Facility ID Number | 10-001-456789 |
| Owner / Operator | Lopez Family Holdings LLC (owner and operator) |
| Tank Information | Tank 001, 10,000 gal regular unleaded; Tank 002, 8,000 gal premium |
| Closure Method | UST Removal |
| Contractor | ABC Tank Services, License No. 845512 |
| Soil Samples | Lab report attached, no release detected |
| Disposal | Manifest for tank bottoms; tanks sent to scrap recycler |
| Date Permanently Closed | 05/12/2026 |
| Signature | Signed Maria Lopez, Managing Member, 05/12/2026 |
Scenario 2: Janet Okafor closes one tank in place under a building
| Form Section | What Janet Enters |
|---|---|
| Facility Name and Address | Okafor Auto Care, 88 Mission Street, San Francisco, CA 94105 |
| Facility ID Number | 10-002-778120 |
| Owner / Operator | Okafor Auto Care LLC, operator Janet Okafor |
| Tank Information | Tank 001, 6,000 gal waste oil, installed 1/1/1900 (unknown) |
| Closure Method | UST Permanent Closure on Site (closure in place) |
| Contractor | Coastal Environmental, License No. 712340 |
| Soil Samples | Borings around tank, no contamination above limits |
| Disposal | Residual sludge manifested; tank cleaned and filled with inert slurry |
| Date Permanently Closed | 05/18/2026 |
| Signature | Signed Janet Okafor, Managing Member, 05/20/2026 |
Scenario 3: David Chen, a consultant, files a closure where a release was found
| Form Section | What David Enters |
|---|---|
| Facility Name and Address | Eastside Truck Yard, 2200 Cesar Chavez St, San Francisco, CA 94124 |
| Facility ID Number | 10-003-902551 |
| Owner / Operator | Eastside Logistics Inc., filed by consultant with written authority |
| Tank Information | Tank 001, 12,000 gal diesel, installed 03/2001 |
| Closure Method | UST Removal |
| Contractor | Pacific Tank Removal, License No. 660917 |
| Soil Samples | Lab report shows TPH above limits, release reported |
| Disposal | Contaminated soil manifested; case opened with Water Board |
| Date Permanently Closed | 04/30/2026 |
| Signature | Signed by David Chen, Authorized Agent, 05/06/2026 |
How to File the Completed Form
California closure filings move through your local CUPA plus the state CERS portal, and you should use both channels to fully close the record. Confirm fees with your CUPA, because they are set locally and change yearly.
- Online (CERS portal): Submit the closure at cers.calepa.ca.gov by logging in, starting a facility submittal, and following the closure steps. There is no separate CERS fee; processing depends on CUPA review, often one to several weeks. Keep the on-screen submittal confirmation as your proof of filing.
- Permit application to the CUPA: Submit the closure/removal permit application before any field work, by the method your CUPA accepts. Riverside County, for example, allows electronic plan submittal by Dropbox to USTPlancheck, while LA County accepts applications by email to ust@pw.lacounty.gov or by mail. Closure permit fees vary by county and tank count; pay by the method the CUPA lists, and keep the issued permit, which may be valid for only 90 days.
- In person or by mail: Many CUPAs accept paper application packages at their office counter. Bring or send the full package with all attachments, request a date-stamped copy, and keep it as proof of filing.
For each channel, retain your stamped permit, the CERS confirmation number, and a copy of the full package. The single most important proof to keep is the CUPA closure letter, which the agency issues after it reviews everything, as noted in the Merced County closure guidance.
What Happens After You File
After you submit, the CUPA reviews your package for completeness and accuracy, checking the soil results, manifests, and CERS entries against its records. The State Water Board’s audit checklist confirms that CERS shows the right answers: Column H (Owner or Operate UST) is N, Column J (UST Reporting Requirement) is Not Applicable, and Column N (UST Permanently Closed Date) holds a date, per the State Water Board closure page.
If everything is in order, the CUPA issues an Underground Storage Tank Closure Letter to the owner, which is your formal proof the tank is closed and your regulatory duties are met. If the file is incomplete, the CUPA returns it with conditions, and you must resubmit corrections; until then the tank stays open and fees can keep accruing.
When a release was found, the matter shifts to the Leaking UST cleanup track, and you keep working with the regulator until the site reaches case closure. Keep the closure letter permanently, because buyers, lenders, and future regulators will ask for it during any property transaction.
Mistakes to Avoid When Filling Out the Form
- Filing more than 30 days after closure — the late submittal can draw penalties and keeps the tank legally open.
- Closing the wrong Tank ID — an active tank shows as closed and a closed tank shows as active in CERS.
- Leaving the closure date blank — the State Water Board audit flags any missing Column N date as an invalid closure.
- Skipping the second CERS facility closure submittal — the site stays a regulated UST facility and fees keep billing.
- Using an unlicensed contractor — the closure becomes unpermitted and subject to enforcement.
- Omitting soil sample results — the CUPA rejects the package and may require re-excavation.
- Losing the hazardous waste manifest — there is no proof of lawful disposal and the file stays open.
- Checking both removal and closure in place — contradictory methods void the permit.
- Entering a mailing address instead of the tank site — the filing routes to the wrong jurisdiction.
- Leaving the signature unsigned or undated — the form is treated as never filed.
- Not reporting a detected release — concealing contamination triggers serious liability and penalties.
- Using an expired closure permit — many county permits lapse after 90 days, forcing a re-application.
Do’s and Don’ts
Do: – Do get the closure permit approved before any field work begins, because unpermitted closures are violations. – Do confirm your contractor’s license is active and certified, since the owner is liable for unpermitted work. – Do take soil samples at the locations the CUPA specifies, as wrong locations cause rejection. – Do complete both CERS submittals when closing the last tank, or the record stays open. – Do keep your CUPA closure letter forever, because it is your proof during any sale. – Do enter the true field completion date as the closure date, since it starts your 30-day clock.
Don’t: – Don’t assume physical closure ends your duties, because the record stays open until paperwork is done. – Don’t name your contractor as the owner, since it misassigns legal liability. – Don’t guess at the Facility or Tank ID, because errors close the wrong tank. – Don’t hide a detected release, as concealment carries severe penalties. – Don’t let the closure permit expire, since lapsed permits force a costly re-application. – Don’t skip the disposal manifests, because without them the file cannot close.
Pros and Cons of Filing on Your Own vs. With a Consultant
| Filing on Your Own | Filing With a Consultant or Contractor |
|---|---|
| Saves consultant fees, which helps a small owner on a tight budget | Costs more, but the fee is small next to a rejected filing or a missed release |
| Full control over the timeline, so you file when you are ready | The pro manages the timeline and the 90-day permit window for you |
| Builds your own understanding of the CERS system for future filings | Brings deep CERS and CUPA experience that avoids common rejections |
| Works for a simple single-tank removal with clean soil | Far safer for multi-tank sites or any sign of contamination |
| You depend on your own reading of changing local rules | The pro tracks county-specific forms and revision dates for you |
| Risk of missing a required sample or manifest is higher | Proper sampling and manifesting are handled correctly the first time |
FAQs
Do I have to file the closure report even if I closed the tank myself?
Yes. Even after physical closure, you must update CERS and file with your CUPA within 30 days, or the tank stays legally open and fees keep accruing.
Do I write the corporate headquarters address in the Facility Address field?
No. Enter the physical street address of the tank site, because that address sets which CUPA has authority over your closure.
Do I use the same number for the Facility ID and the Tank ID?
No. The Facility ID covers the whole site, while each tank has its own separate Tank ID, and mixing them closes the wrong record.
Do I enter today’s date or the permit date as the closure date?
No. Enter the date the physical closure work finished, because that date starts your 30-day CERS filing clock.
Do I check both “Removal” and “Closure in Place” if I am unsure?
No. Check only one method, since the two carry different requirements and checking both voids the permit.
Do I need soil samples if the soil looks and smells clean?
Yes. Sampling is mandatory because petroleum contamination is often invisible and odorless, and the CUPA will reject a package without lab results.
Do I have to report contamination found during closure?
Yes. A detected release must be reported, which opens a Leaking UST cleanup case, and concealing it brings serious penalties.
Do I need a licensed contractor, or can I close the tank myself?
Yes. California requires a properly licensed and certified contractor for the physical closure work on a regulated UST.
Do I file only one CERS submittal when closing my last tank?
No. You file two submittals — one documenting each tank closed and one confirming no regulated USTs remain at the site.
Do I get penalized for filing late?
Yes. Late or incomplete filings can draw penalties that reach thousands of dollars per tank per day and keep the tank legally open.
Do I keep the closure documents after the CUPA issues its letter?
Yes. Keep the closure letter permanently, because buyers, lenders, and regulators ask for it during any property transaction.
Do I enter a date if I do not know when the tank was installed?
Yes. When the install date is unknown, enter 1/1/1900 as the State Water Board instructions direct, rather than leaving the field blank.
Related reading
- How to Fill Out Florida DEP Underground Storage Tank Registration + FAQs
- How to Fill Out the Washington Ecology Underground Storage Tank 30-Day Notice + FAQs
- How to Fill Out the Washington Ecology Underground Storage Tank 30-Day Notice (Form ECY 020-95)
- How to Fill Out the Ohio EPA / BUSTR Underground Storage Tank Registration Application (Form SFM-17-0033 / COM5211) + FAQs
- How to Fill Out the NJDEP Underground Storage Tank Registration (USTFCQ) + FAQs
- How to Fill Out North Carolina DEQ Underground Storage Tank Notification (Form UST-8) + FAQs
- How to Fill Out the Washington Ecology Water Quality Modification Permit + FAQs