A permit to discharge industrial wastewater to the sanitary sewer is required for certain types of industrial facilities. Every commercial or industrial facility is considered to be an industrial user and Grand Prairie regulates all wastewater discharge from certain types of industrial facilities:
- General Industrial Users
- Monitored Industrial Users
- Significant Industrial Users, Categorical and Non-Categorical
General Industrial Users (IU) include any industrial or commercial facility that discharges wastewater into the City’s sanitary sewer. This type of facility is subject to on-site inspections upon opening and every couple of years. These industries are not subject to the federal categorical pretreatment regulations, do not fit the definition of a significant industrial user, and a permit to discharge wastewater to the sanitary sewer is generally not required. The City has the right to permit, inspect and monitor any of these facilities at any time and all facilities must comply with all applicable environmental regulations.
Monitored Industrial Users (MIU) are those facilities whose process and wastewater discharges do not necessarily fall under the categorical pretreatment regulations or the definition of a significant industrial user, but are of special interest to the City. Some examples are food manufacturers and box manufacturing and printing. These types of facilities do not require a permit to discharge wastewater; however, they are inspected annually and are monitored by the City for pollutants of concern.
Significant Industrial Users (SIU) are sources of industrial wastewater that, by federal regulation, require an increased level of regulatory attention. An SIU is defined as an industrial user that meets any one of the following criteria:
- Is subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 40 CFR Chapter I, Subchapter N.
- Discharges an average of 25,000 gallons per day or more of process wastewater to the City’s sanitary sewer.
- Contributes a process waste stream that makes up 5 percent or more of the average dry weather hydraulic or organic capacity of the wastewater treatment plant.
- Is designated as such on the basis that the industrial user has a reasonable potential for adversely affecting the operation of the treatment plant or the City’s collection system, or for violating any pretreatment standards or requirements.
SIUs must obtain a wastewater discharge permit to discharge any industrial wastewater to the City’s sanitary sewer. A wastewater discharge permit application is required 60 days prior to commencement of discharge.