Cold Water Creek Geothermal Plant – Demolition

PROJECT DETAILS

On August 7, 2000, work began on the blasting of the Coldwater Creek turbine / generator pedestals in the Central California Power Agency Plant #1, located near Kelseyville, CA., in a region known as “The Geysers.”  The plant was built in 1988 and operated until  it was decommissioned in 1994 because of inefficiency in its operation.

The Coldwater Creek generator facility was a dry steam geothermal power plant.  Work is currently underway to remove the power plant and restore the area around it to the original state prior to construction.

What is Geothermal Energy?

Geothermal energy is renewable heat energy from deep in the earth. Heat is brought to the near-surface by thermal conduction and by intrusion into the earth’s crust of molten magma originating from great depth. Ground water is heated to form hydrothermal resources – naturally occurring hot water and steam. Use of hydrothermal energy is economic today at a number of high-grade sites. Hydrothermal resources are tapped by existing well-drilling  and energy-conversion technology to generate electricity or to produce hot water for direct use.  Earth energy is used by geothermal heat pumps. Hot dry rock, magma and geopressured geothermal energy have enormous potential.

For generation of electricity, hot water, at temperatures ranging from about 300deg.F to more than 700deg.F, is brought from the underground reservoir to the surface through production wells, and is fed to a turbine engine, which turns a generator. Spent geothermal fluid is injected back into peripheral parts of the reservoir to help maintain reservoir pressure.

Plant Reclamation of Richmond, California is heading up the demolition project.  The Company’s president, Bill Glueck, decided that blasting these huge foundations was the best way to remove them.

Dykon Blasting was then contracted to assist Plant Reclamation in the demolition of the foundations.

The building itself was left in place until after the foundations are blasted.  This is being done to prevent concrete from the foundations being sprayed out into the surrounding area and left in the environment.  Every effort is being made to restore the area to it’s original state.

When all the equipment inside the powerhouse was removed and nothing remained but the generators and turbines on the pedestals, Dykon Blasting returned to the project to explosively demolish the pedestals.

These reinforced concrete turbine foundations were designed to earthquake standards.  The goal of the blasting was not only to fragment the concrete, but to bring the half million pound steam turbine / generators down to a point where they could be safely removed.

The legs of the foundation would have to be completely blasted out from under the units in order for them to fall.  On November 10th, 2000, Dykon test blasted the heaviest of the center columns on the far west foundation.

Because of the earthquake resistant design, Dykon loaded the concrete in the test column at twice the amount of explosive that would normally be required to blast reinforced concrete.

The picture above clearly shows that this is no ordinary reinforced concrete.  The concrete in the column was fragmented but the reinforcing steel held it together.  These columns had to be completely removed in order for the turbines to fall.

A second test column was loaded and shot the same day.  The picture to the right shows that this was a successful test.  Dykon, with the help of Plant Reclamation would now move forward with the production blasting.

The first foundation was loaded and shot Saturday morning, November 11th.  1205 pounds of explosive was loaded into 110 blastholes.

The second foundation was loaded with just under 1400 pounds of explosive in 110 blastholes and was blasted late the same afternoon.

We at Dykon Blasting would like to express our thanks to Plant Reclamation for helping make this project a successful one.  Their cooperation and assistance made it all possible.  A special thanks goes out to Bill, Nick and Jose who were onsite with us throughout the blasting.