SWPPP for a New Facility, a Closure, or an Ownership Change

“We just acquired this facility.” That call comes in often, and it usually arrives with the same assumption: the stormwater permit came with the building. It didn’t.

Opening a site, closing one, or changing who owns it all affect your stormwater coverage, even when the day-to-day operations stay exactly the same. The permit ties to the operator and a state-issued ID number, not to the address or the equipment on the floor. So a change at the top of the org chart can leave you out of compliance without anyone touching the production line.

Here is what each scenario requires under California’s Industrial General Permit (IGP, Order 2014-0057-DWQ), the statewide stormwater permit administered by the State Water Board.

Why a Facility Change Triggers a Stormwater Review

Your coverage under the IGP runs through a WDID number (the Waste Discharge Identification number the state assigns when you enroll) and a Legally Responsible Person who certifies your filings. When ownership, the operating company, or the responsible person changes, those records no longer match reality. The state still expects annual reports, sampling, and fees under that WDID until someone formally closes it out or claims it.

This is why a facility change is worth a stormwater review even if you make the same product the same way the day after the deal closes. The question is never “did operations change.” It’s “do the permit records still reflect who is actually running this site.”

SMARTS, referenced above, is the state’s online stormwater reporting portal where every filing in this table happens. For a complete overview of how coverage works, see our SWPPP and stormwater compliance services in California guide.

Opening a New Facility

A new site that conducts a regulated industrial activity needs its own coverage before it starts operating. That means filing a Notice of Intent (NOI) in SMARTS, receiving a new WDID number, and having a SWPPP developed and certified before the first rain you would otherwise need to sample.

Two points catch new operators off guard. First, a SWPPP is site-specific. You cannot copy the plan from another location you own, because the drainage areas, materials, and discharge points are different at every address. Second, not every facility needs the full permit. Some qualify for a No Exposure Certification (NEC), which applies when industrial materials and activities are not exposed to rain. If you are not sure whether a new site is covered at all, start with whether your facility needs a stormwater permit before you build anything.

When we walk a newly opened site, the first thing we map is the discharge points: where does rain actually leave the property, and what does it pass over on the way out. That determines the sampling locations and half of the BMPs the plan will need.

Closing a Facility

Shutting down a site does not close your permit. You stay on the hook for annual reports and annual fees under that WDID until you file a Notice of Termination (NOT) in SMARTS and the Water Board accepts it. We regularly find old permits that were never terminated, quietly accruing fees years after a facility stopped operating.

A NOT applies when you have discontinued industrial activity at the site or transferred it to a new operator. Filing it promptly is the only way to stop the obligations and the billing. Until the termination is approved, the facility is still your responsibility.

Buying or Selling a Facility

There is no clean handoff of a stormwater permit between a buyer and a seller. The permit does not ride along with the deed. The previous operator (the permit calls this the ‘Discharger’) files a Notice of Termination, and the new operator files a new NOI to obtain a new WDID number under their own company. The new operator then needs a SWPPP written under their name, even if the prior owner’s plan was perfectly good.

When a client calls after an acquisition, the first thing we check in SMARTS is whether the seller ever filed that termination. Often they didn’t, which leaves an open permit attached to a company that no longer runs the site and a buyer operating with no coverage of their own. Both sides have a gap, and neither knew it at closing.

For companies acquiring several California sites at once, this repeats per location. Each address is its own permit, its own WDID, and its own plan. There is no portfolio-level shortcut. Reporting for all of them runs through the same portal, which is worth understanding before the first deadline arrives: how SMARTS reporting works.

Where Stormwater Fits in a Larger Facility Change

Stormwater is rarely the only program affected when a facility opens, closes, or changes hands. The same event usually moves your hazardous materials inventory, your waste generator status, and your other permits. An EHS gap assessment is the cleanest way to catch all of it at once, rather than discovering the open stormwater permit a year later when the fee notice arrives. Acquisitions and closures also drive hazardous waste management and facility setup, closure, and ownership change obligations that share the same triggers as your stormwater coverage, and they are two of the places where stormwater compliance connects to your other California EHS programs.