Background

MHWSC operates six looped distribution areas with pressure zones supported by one or more elevated storage tanks or one of its seven booster pump stations to provide adequate drinking water service to its customers. Each booster pump station requires at least one ground storage tank that meets capacity requirements for its relevant service demand and, ideally, includes two such tanks to provide redundancy and better maintenance capabilities. MHWSC meets the standards when all its infrastructure is in service.

A portion of the MHWSC water distribution system in Hidalgo County has been experiencing regular water outages and low-pressure incidents due to the deteriorated conditions of two ground storage tanks. The Santa Ana and Moore Road Booster Stations were built in 1998 and 2000, respectively. Both stations have dual storage tanks for normal operation and maintenance purposes; however, the existing tanks have exceeded their useful life, are prone to leaks and their interior walls are corroded, impacting the quality of the water entering the distribution system. The tanks require frequent repairs, resulting in incidents of low pressure and water outages and requiring the utility to issue boil notices.

In March 2023, one of the tanks at the Moore Road booster station was placed out of service to prevent further risks to water quality. While taking one tank out of service will not immediately impact regulatory compliance for storage capacity, this situation compromises system reliability and increases its vulnerability to service interruptions, especially in the face of increasing demand due to the hot, dry conditions prevailing in the project area. It also affects the utility’s capacity to maintain adequate pressure requirements. During 2022 and 2023, the utility experienced 89 water outages, recorded 170 low-pressure incidents and issued two boil water notices in the project area.

Description

The project consists of removing and replacing a ground storage tank at both the Santa Ana and Moore Road Booster Stations. The construction activities for both sites include:

• Demolition of the existing 150,000-gallon storage tank.
• Construction of 150,000-gallon, galvanized steel storage tank.
• Replacement of associated piping and valves.

Benefits

Providing adequate water storage capacity will improve access to sustainable and reliable drinking water service for 2,377 existing residential connections by reducing the risk of water outages, incidents of low pressure and potential cross-contamination problems that increase the risk of waterborne diseases. The improvements will allow the utility to maintain regulatory compliance for water pressure and quality.