Does your Gilbert business need a Class A or Class B wastewater discharge permit?

Section 66-232 covers the "class A" permit. Subsection (a) says each industrial user who discharges an industrial discharge into the sewer system and is designated a significant industrial user (SIU) by the director shall do the following:

1. 1Obtain a class A wastewater discharge permit from the director, and apply for a new or amended permit at least 90 days before starting any new or additional industrial discharge, as the quote above says.
2. 2Provide all the pretreatment needed to meet the categorical standards, pretreatment requirements and best management practices in the article.
3. 3Meet the prohibited-discharge rules in 66-231(b).
4. 4Keep every discharge under the local limits, stated as daily averages in total form: arsenic 0.13, cadmium 0.047, copper 1.5, cyanide 2.0, lead 0.41, mercury 0.0023, selenium 0.1, silver 1.2 and zinc 3.5, all in milligrams per liter. The table's footnote says the limits are applied at a sampling location the director determines.
5. 5Keep a continuous discharge record of dates, times, nature, concentrations and volumes, and send the director the same self-monitoring reports sent to any other authority.
6. 6Keep those records at least three years from the monitoring date, longer during unresolved litigation with the town's treatment works.

Section 66-233 adds the "class B" permit. Non-significant users "may be required" to get one "if the director determines the industrial discharge causes or has the reasonable potential to cause harm or damage" to the town's sewer works, worker safety, public safety or the environment. A class B holder follows the same local limits, pretreatment, prohibited-discharge, record and reporting rules.

Section 66-187 supplies the mechanics. No significant industrial user may connect to the town's sewage system until a class A or class B permit is obtained. A permit is valid for up to five years. The application goes on the director's form with a nonrefundable fee set by council resolution, and it includes a plat of on-site sewers, sampling points and pretreatment, a product list, a state-certified lab analysis of the effluent, and a permit discharge report.

• Industrial discharge: wastewater other than domestic wastewater that comes from a source subject to categorical standards or pretreatment requirements, or that contains a pollutant with a discharge limit.
• Significant industrial user: a user subject to federal categorical pretreatment standards, or one that averages 25,000 gallons per day or more of process wastewater, or contributes a stream making up five percent or more of the treatment plant's average dry weather capacity, or one the director designates because it could harm the plant or violate a standard.
• Zero process discharge user: a user that only discharges domestic waste but would be subject to categorical standards if it discharged process wastewater.
• Director: the director of the department of public works or the director's designee.
• How a business learns it is designated: the sections read here do not say. Our reading is that you ask the town before you sign a lease or order equipment.

Industrial users: sources of industrial discharge, users above the equivalent strength of 25,000 gallons per day of domestic waste, and significant industrial users. The code separately defines a "commercial user" as a user that provides a service connected with commerce and is not classed as an industrial user, and it names home-based businesses, non-profit organizations and schools as examples.

This does not apply the same way if the director finds a categorical user never discharges more than 100 gallons per day of categorical wastewater and the conditions in the definition are met. That user is a non-significant categorical industrial user, not an SIU.

A manufacturer moving into a Gilbert industrial building. If its process is covered by a federal categorical standard, it is an SIU and needs the class A permit before it connects. Everything starts with the application, the plat and the lab analysis.

A plant adds a second production line. The new line's wastewater is an additional industrial discharge. If the existing permit already allows it, no new application is needed. If it does not, the amended permit is due 90 days before the line runs.

The edge case: a facility that makes no process wastewater at all. It sends only sinks and toilets to the sewer, but its operations would be categorical if they produced process water. The code names this a zero process discharge user, so the director can still require a class B permit. Saying we discharge nothing industrial is not the end of the question.

1. 1Decide whether your wastewater is more than domestic. If any process water leaves the building, call the Town of Gilbert at (480) 503-6000 and ask for Public Works, whose director issues these permits.
2. 2Count back 90 days from the first day you will discharge and treat that as your filing deadline.
3. 3Gather the application pieces from 66-187(e): the plat, the product and chemical list, a state-certified lab analysis and the permit discharge report.
4. 4If you are a new source, install and start up your pollution control equipment before discharging. The code gives 90 days to meet applicable pretreatment standards and requires a baseline monitoring report before discharge starts.
5. 5After issuance, start the discharge log and keep records three years.

• Every business with a floor drain needs a Class A permit. The class A permit is for designated significant industrial users. Food service has its own rules in 66-244.
• Class B is the light version. Section 66-233(b) applies the same local limits and the same record and reporting duties.
• We can start while the application is pending. The code asks for the application at least 90 days before the discharge begins, and 66-187(a) bars a significant industrial user from connecting without the permit.
• The permit is open-ended. It is valid for up to five years from issuance, including a renewal.

Gilbert's own text governs; this page explains it.