Hoover Dam Activities

Hoover Dam is currently the Reclamation facility least-affected by quagga mussels on the lower Colorado River. However, colonization is happening - inspections conducted during the 2007-2008 maintenance period revealed mussel communities in certain for the smaller water-supply pipelines used to cool off generators, compressors, transformers also equipment in the dam. Furthermore, colonization on a number of the dam’s outside surfaces, like intake tower walls, in addition has increased.

The colonization that includes taken place to date have not affected the dam’s energy generation or water delivery features, or needed any extraordinary maintenance. To cut back the possibilities that enhanced and constant maintenance is going to be needed seriously to deal with the mussel infestation, Reclamation has developed and is implementing a proactive quagga mussel control program.

Initial concern of this program should increase tracking tasks to pinpoint in which colonization is occurring and also at exactly what price. Consequently, Reclamation has actually:

• installed a substrate system on the intake towers to demonstrate how fast colonization is occurring;
• increased underwater inspections of outside surfaces from semi-annually to month-to-month; and
• installed bio-boxes on two cooling liquid lines that have already shown indications of colonization.

Another concern would be to, over the following 12 months, purchase and install a strainer and ultra-violet system or a 50-micron Self-Cleaning Filter on dam’s domestic water supply line, which delivers drinking water toward facility and visitor center. The Self-Cleaning Filter has-been put in and it is increasingly being tested at Parker Dam.

These control measures would also be installed on methods who supply air conditioning liquid to generator bearings, heat exchangers, air compressors, equipment in elevator machine spaces, company roof coolers also, similar gear.

Reclamation can also be considering several prospective long-lasting control steps that would be implemented at Hoover Dam. These generally include:

• Making use of liquid from tailbay (the area below the dam where water exits the generators) when it comes to dam’s cooling water supply. The cooling water when it comes to dam’s systems now comes directly from Lake Mead. Nevertheless mussel population underneath the dam is significantly less than it really is in Lake Mead, above the dam. This method could be created and constructed with certain obstacles - small strainers, self-cleaning filters, ultra-violet light systems - to deal with the water prior to it being delivered to running gear inside the powerplant.

• Making use of covered metals, anti-fouling material coatings, or nasty release coatings to deter or avoid the mussels from attaching to particular areas. Reclamation is carrying out a study regarding the effectiveness of various kinds of steel coatings at Lake Havasu, on the upstream part of Parker Dam.

• Testing a freshwater bacterium that contains a toxin recognized to destroy the digestive tract of zebra mussels, a close relative associated with quagga, by providing it something similar to a deadly bleeding ulcer. The bacterium, which cannot hurt other aquatic life, is being tested at Hoover Dam to determine its effectiveness as a mussel control agent. The test has been coordinated by Reclamation’s Research and Development office in Denver, Colo.