Groundwater Discharge Permit/One-time Permit

Groundwater Discharge Permit

A groundwater discharge permit is required for remediated groundwater discharges to the City sanitary sewer system. Permits are issued for groundwater remediation projects which discharge to the sanitary sewer over a period of time. A permit application for disposal of treated groundwater into the City sanitary sewer system must be completed and signed by the operator of the treatment system. In addition to the completed application, the following information must be submitted to the Pretreatment and Laboratory Services (PALS) Division, Liquid Waste Program.

1. A summary stating the need to discharge groundwater into the sanitary sewer system.
2. A copy of the Texas Commission on Environmental Quality (TCEQ) Administrative Order or Voluntary Cleanup Program.
3. A detailed description of the treatment system that includes method of remediation, rates of removal, type of equipment to be utilized, plumbing plan and pretreatment process flow.
4. The frequency of discharge (average and maximum gallons per minute) and the estimated volume of discharge (monthly).
5. The location of the contaminated area on a plan view map along with the monitoring wells and recovery wells. A groundwater analytical report must be submitted for all monitoring wells identified on the map.
6. The location of the sampling site. An approved sample pad may have to be installed.
7. A description of an emergency spill plan describing the method of containment that will be used. The containment should be leak proof and of sufficient height to retain 110% of the volume of the contaminated water within the treatment compound.
8. Identify on the plan view map where you plan to connect to the sanitary sewer.
9. Analysis for Table II, III, and V parameters as found in 40 CFR 122. All concentrations must comply with concentration standards established by Chapter 49 of the City Code, “Water and Wastewater” and/or maximum allowable concentration established by the City. All levels of treatable organic compounds shall be at or below detection limit and no analytical results shall ever exceed local ordinance limits. All pollutants of concern identified in the initial scan must be treated to or below detection limits and in no case shall exceed local ordinance limits.
10. Documentation of the laboratory Quality Assurance Program is required.
11. A schedule of maintenance for the pretreatment system.

In addition to a one-time baseline analysis of the pollutants listed in40 CFR 122 Appendix D Table II, III and V, PALS requires that monthly self-monitoring be conducted for pollutants of concern determined prior to approval for discharge. The monthly report should also include the monthly volume discharged and is due on the 15th of every month. DWU reserves the right to collect random samples independent of the self-monitoring to ensure that compliance is being maintained. If violations occur, the discharge must cease and corrections to the treatment must be made until compliance is met. More frequent sampling may be required at the expense of the permittee.

A normal sewer rate specified in Dallas City Code Volume II, Chapter 49, Sec 49.18.2 shall be assessed. The rates are based on the meter size and the volume discharged to the sanitary sewer. Additional rates will apply for excessive concentration of conventional pollutants. Dallas Water Utilities may require that excessive discharges into the sanitary sewer system be metered by an approved method. If a connection to the sanitary sewer system is required, please contact the Permit Center Office at (214) 948-4500. To facilitate this process, the following information will be required:

• Account name
• Service Address
• Mailing Address
• Area code & Phone number of contact person
• Name of Contact Person
• Tax ID#

One-Time Groundwater Discharges

One-time discharges are approved on a case by case basis. The following information must be submitted for the one-time discharge of remediated groundwater into the sanitary sewer system:

1. A summary stating the reason for discharge into the sanitary sewer system.
2. Previous analytical data compiled from remediation site, specifically for pollutants of concern.
3. A description of the treatment system that includes method of remediation, type of remediation equipment to be utilized, purpose of equipment and rates of removal. In addition, a diagram of the treatment system that includes a plumbing plan, pretreatment process flow diagram and location of groundwater to be remediated.
4. The estimated volume of discharge (average and maximum gallons per minute).
5. The hours of operation of the treatment system and the estimated period for completed discharge.
6. The connection to the sanitary sewer. Identify on a map where you plan to connect to the sanitary sewer system.

If results of analytical tests from 40 CFR 122 Appendix D Table II, III and V comply with wastewater discharge limitations established by the Dallas City Code Volume II, Chapter 49, Article IV, Sec 49-42, then approval for one-time discharge to the sanitary sewer system may be granted. Pretreatment and Laboratory Services Division reserves the right to conduct sampling at the expense of the discharger. A final invoice reflecting the cost of sampling and laboratory analysis will be sent to you from Dallas Water Utilities.