TECHNICAL BULLETIN

TEXAS COMMISSION ON ENVIRONMENTAL QUALITY WATER STORAGE TANK CONSTRUCTION COMPLIANCE

(3/13/2015)

This bulletin is intended to present a summary of details that a designer of a water storage tank should follow if the tank is to meet the requirements of the Texas Commission on Environmental Quality (TCEQ). This summary is based on Title 30 - Environmental Quality, Part 1 of the Texas Commission on Environmental Quality, Chapter 290 for Public Drinking Water, Subchapter D Rules and Regulations for Public Water Systems. 1. The water system, including the amount of water required in storage, piping, controls, purification,

pumps, distribution, etc. must first be designed by a Texas licensed engineer. Unless the water system design engineer is competent to also design water storage tank structures and foundations, then a different licensed engineer will be required to design the water storage tank and foundation.

The water tank storage capacity and location must be determined by the water system engineer and approved by TCEQ before the design of the water tank structure and foundation can commence.

2. The water storage tank structure and foundation must be designed for the specific project site and the

design must be stamped by a Texas licensed engineer.

TYPICALLY THE ABOVE TWO STEPS ARE SEPARATE DESIGN PROCESSES INCORPORATING TWO DIFFERENT LICENSED ENGINEERS.

OTHER TCEQ REQUIREMENTS FOR POTABLE WATER STORAGE TANKS 3. Concrete floor or ring beam foundation over engineered earth above the groundwater table.

4. Low-profile or gooseneck roof vent with 16-mesh corrosion resistant insect screen. Vent to be sized to

provide makeup air for maximum potential water outflow from tank.

5. Minimum 30” diameter roof access for personnel access into tank with 4” curb and lockable cover.

6. Minimum 24” diameter roof opening for ventilation during any personnel access into tank.

7. Overflow sized to handle the maximum possible fill rate without exceeding the capacity of the overflow opening. Overflow to terminate with a gravity hinged and weighted cover above the surface of the ground and not subject to submergence.

© 2015 Water Storage Tanks, Inc. All rights reserved.

8. Liquid level indicator which may be a float-and-moving-target type, ultrasonic or pressure gauge calibrated in feet of water.

9. Drain fitting at lowest point inside of tank. Drain may not be connected to any waste or sewage disposal system.

10. Tank exterior structure may be galvanized or painted.

11. Interior liner to promote removal of condensation from inside of tank wall structure.

12. NFP-61 approved flexible membrane water containment liner.

13. Tank fill pipe to terminate 2” below roof sheet to provide minimum of 6” air gap above side wall overflow fitting.

14. Designed to AWWA D103 structural standards for bolted steel tanks with AWWA D130 flexible membrane liner.

15. Roof slope of 10 to 30 degrees exceeds 0.75 inch per foot.

16. Sidewall access panel for access for major cleaning.

© 2015 Water Storage Tanks, Inc. All rights reserved.

© 2015 Water Storage Tanks, Inc. All rights reserved.

© 2015 Water Storage Tanks, Inc. All rights reserved.