Do breweries need to pretreat wastewater in Phoenix?

Section 28-8 of the Phoenix City Code lists what no user may send to the city's treatment system, which the code calls the POTW (publicly owned treatment works). Several items line up with what a brewhouse puts down the drain.

• pH. The code bans "Water with a pH less than 5.0 standard units (S.U.) or greater than 10.5 S.U." Caustic cleaning cycles push pH up. Acid rinses and sanitizers pull it down.
• Oxygen demand. It bans pollutants, "including oxygen demanding pollutants (BOD, etc.)," released at a flow rate or concentration that could cause interference with plant operations or pass-through. BOD, or biochemical oxygen demand, is a measure of how much food the waste gives to bacteria. Wort, beer and yeast are loaded with it.
• Heat. It bans water hotter than 150 degrees Fahrenheit. Hot cleaning water can reach that.
• Solids. It bans solid or viscous pollutants that can obstruct flow in sewers. Spent grain, trub and yeast slurry fit that description when they go down a floor drain.
• Dilution. It bans diluting waste with extra water "as a partial or complete substitute for effective pretreatment." Running a hose to meet a limit is itself a violation.

These local rules sit on top of federal ones. EPA's general and specific prohibitions "apply to all nondomestic dischargers that discharge wastewater to a publicly owned treatment works," whether or not the business holds a permit. They include a floor of pH 5.0 and a ban on oxygen-demanding pollutants that cause interference with the plant.

Not every brewery needs a permit, but the threshold is closer than many owners expect. Section 28-45 splits industrial users into permit classes.

A Class A permit is for significant industrial users. Phoenix's permitting page lists, among others, "Companies that discharge an average 25,000 gallons per day of process wastewater to City sewers," and companies whose effluent could affect the treatment plants.

A Class B permit can be required of users who aren't significant industrial users when the Director finds the discharge could harm the system, workers, the public or the environment. The first example in the code is "Users that discharge the equivalent strength of 25,000 gallons per day of domestic waste as measured by BOD and TSS." TSS is total suspended solids. The point is strength, not volume. A brewery that sends far fewer gallons can still hit that line, because its BOD is so much higher than household sewage.

The timing rules are strict:

1. 1Apply 90 days ahead. The city's FAQ says a business starting any new industrial discharge "must apply for a new or amended permit at least ninety days prior to initiating such discharge(s)." Permits last up to five years.
2. 2Plans go to pretreatment staff first. Phoenix says construction drawings for industrial facilities "must be submitted for review and approval by the City of Phoenix Industrial Pretreatment Program (IPP) prior to submittal to the City of Phoenix Planning Development Department."
3. 3No building before approval. Where the Director requires pretreatment, Section 28-10 says construction can't begin until the user gets written approval, and the system can't run until the city inspects it.

To find out where you stand, Phoenix points businesses to its permitting flowchart and to the pretreatment program at 602-495-5926 or IPP.PlanReview@phoenix.gov.

Brewing sends most of its water to the drain. Ohio EPA's brewery fact sheet says about seven of every ten gallons of incoming water leave a brewery as effluent. The same sheet says brewing effluent "is highly organic and can be expensive for POTWs to treat," and that treatment plants are designed for sewage and sanitary wastewater, not industrial wastewater.

Cleaning chemicals are part of the picture too. The Ohio sheet says caustic cleaners and disinfectants are among the brewery wastes that could be hazardous and "cannot be managed through the POTW."

Phoenix bills for that strength. City Code Section 28-34 says the treatment plant charge "will be made to all customers on the basis of flow and strength of sewage discharged," with separate rates for BOD and suspended solids. The rate table in Section 28-39 lists a "Charge per Pound of BOD" and a charge per pound of suspended solids. Section 28-36 lets the city sample a commercial user's discharge, and a user whose process changes enough to move one of its loading concentrations more than 25 percent must tell the Director within 30 days.

Other Valley cities have similar tools. Tempe's City Code 27-22 lets its Public Works Director require a user "to install and maintain, on their property and at their expense, a suitable storage and flow-control facility to ensure equalization of flow." For a brewery, that often means a tank that smooths out the slug from a cleaning cycle.

Brewery pretreatment is mostly plumbing. It means routing the right drains to the right place before they reach the building sewer.

A taproom with a small brewhouse. Keep solids out of drains with basket strainers and dry cleanup, and neutralize cleaning rinses before they leave. Talk to the city early if your volume is growing.

A production brewery. Plan for a sampling point, pH monitoring and neutralization, and possibly equalization. Expect the pretreatment program to review your drawings before the building permit.

A brewery moving into an old restaurant. An existing grease interceptor is not a pH or BOD treatment system. The drains from the brewhouse may need their own path. For how that works in a shared building, see commercial tenant improvement plumbing.

Whatever you install, you own its upkeep. Phoenix's Section 28-11 says pretreatment systems "must be maintained continuously in satisfactory and effective operation by the user at the user's expense," with records of cleaning, repair and calibration kept on site for at least three years. And the solids you screen out can't go back down the drain: Section 28-8 also bans sending "Sludges, screenings, or other residuals from the pretreatment of industrial wastes" to the sewer.

Dumping a bad batch. Don't send a full tank of beer to the drain. It's a large BOD slug in a short time, the kind of release Section 28-8 bans when it causes interference. Talk to the city or a licensed liquid waste hauler first.

Here's the order we suggest:

1. 1List every drain in the brewhouse. Floor drains, trench drains, tank outlets and the clean-in-place return.
2. 2Estimate daily flow and strength. Your equipment supplier's water use figures are a start.
3. 3Call the Phoenix pretreatment program. Walk through the flowchart before you finalize drawings.
4. 4Design the treatment. Size neutralization and any holding tank to the worst cleaning cycle.
5. 5Build in access. A sampling point and cleanouts make inspections and upkeep easier.

If your brewery also serves food, the kitchen side has its own rules; see what FOG is and whether a coffee shop, bakery or bar needs a grease trap.

HQ Plumbing & Air installs and repairs commercial drain piping, floor and trench drains, and interceptors for Valley businesses, with free estimates and upfront pricing.