The Pre-Treatment Department samples and regulates discharges of all industrial and commercial businesses into the wastewater system.

What Should I Know About MPU’s Industrial Program?

Thank you for inquiring about City of McAllen, McAllen Public Utility’s industrial pretreatment program. We have a knowledgeable, competent staff ready to work with you. MPU provides consistent guidance and technical assistance to keep industrial users in compliance with federal regulations.

Why Does MPU Require Pretreatment?

The USEPA has mandated the use of industrial pretreatment to keep pollutants and substances that disrupt wastewater treatment processes out of the sanitary sewer system, requiring you to control them at the source. MPU is responsible to the Texas Commission on Environmental Quality (TCEQ) and USEPA for regulating and enforcing pretreatment requirements within the City of McAllen City Limits as well as the City of Alton through an Interlocal Agreement. MPU monitors permit compliance on a regular basis. We are required to publish the facility name and type of non-compliance committed by significant violators, annually.
Our enforcement actions can range from a telephone call to the issuance of a civil penalty and request to stop discharging. Industrial pretreatment protects MPU effluent and actually promotes conservation by enabling industrial by products, chemicals and metals to be recycled at the source, and allowing MPU to use its clean biosolids for beneficial reuse for land application.

We look to you to control your process wastewater and help us protect our collective environment.

What Is An Industrial User?

Any person who uses MPU’s system to dispose of wastewater other than sanitary or domestic.

Who Needs a Permit?

If you discharge anything other than sanitary or domestic wastewater, you must contact MPU about a permit. For example, Metal Finishers, Food Processors or process wastewater all require a MPU permit application.

Our permit will establish your reporting requirements and limits for discharging constituents (components, elements) found in your particular industrial waste.

How Do I Get A Permit?

MPU will supply you with a permit application. You must submit a completed discharge application permit at least 90 days before you wish to discharge wastewater. We will review your application, and if all is in order, prepare a discharge permit that lists your discharge and other requirements. To obtain an application, call the MPU Pretreatment Department at 956-688-3382. Ask for a Permit Application or you may obtain an application online.

What Types of Questions Should I Direct To MPU?

• Equipment Review
• Policies and Procedures
• Disposal Options
• Permit Limitations
• Test Methods
• Pollution Prevention Opportunities

What Are Local Limits?

In addition to applicable Federal pretreatment standards, discharges must stay within limits based on local wastewater treatment plant specifics. No Significant Industrial User (SIU) shall discharge wastewater containing concentrations (and/or mass limitations) of substances exceeding the following limits. All SIUs are expected to consistently discharge below these levels:

Constituent Maximum Allowable (mg/L)
Arsenic 0.19
Cadmium 0.14
Chromium 3.69
Copper 3.56
Cyanide 0.52
Lead 1.23
Mercury 0.00 1
Nickel 1.76
Selenium 0.10
Silver 0.80
Zinc 9.29
1 Compliance for mercury will be determined at the minimum analytical level (MAL) of 0.2 μg/L

What Is A Significant Industrial User?

• All Industrial users who are subject to USEPA categorical pretreatment standards, or
• Any industrial user that discharges an average of 25,000 gallons per day or more of process wastewater, excluding sanitary, non-contact cooling and boiler blow-down wastewater, or
• Any industrial user that contributes a process wastestream that makes up 5% or more of the average dry weather hydraulic or organic capacity of a MPU treatment plant

What Is Required Of The Permit Holders?

Significant Industrial Users (SIUs) are required to submit reports to MPU, which are listed in your discharge permit. MPU provides assistance in completing the initial forms for these reports.
Other Requirements
• Notification to MPU of changes in wastewater discharge, process changes or permit violations
• On-going compliance with discharge permit
Possible Requirements
• Pretreatment of process wastewater
• Continuous flow and pH monitoring
• Independent wastewater analysis of permit constituents

How Does the High Strength Surcharge Work?

If you waste exceeds 200 mg/L of Biochemical Oxygen Demand (BOD) or 200 mg/L of Total Suspended Solids (TSS), then fees are levied in addition to actual flow charges. These surcharges are for additional loading. Currently the surcharge fees are:
BOD > 200 mg/L = 0.288
TSS > 200 mg/L = 0.671

How Do I Obtain Technical Assistance?

We work closely with businesses located within our service area and are readily available for technical support. Our staff of wastewater experts will work to achieve mutual goals of safe industrial wastewater disposal. If you are planning a new facility, we may be able to save you some re-design time if you contact us first. With our guidance, your early design can include appropriate waste disposal requirements. Call the Wastewater Pretreatment Department at 956-688-3382 to request assistance.