Environmental review to forward Ormats Casa Diablo project this spring

Mammoth Pacific geothermal power plant, Ormat/ Constellation (source: Mammoth Pacific)
Alexander Richter 30 Apr 2011

Ormat is moving forward with its Casa Diablo Geothermal Project, after having drilled two exploratory wells to determine the feasibility of a new 33-megawatt geothermal power plant, last summer. This spring, the project is undergoing environmental review.

In news from California, it is reported that “Ormat drilled two exploratory wells in Shady Rest Park to determine the feasibility of a new 33-megawatt geothermal power plant, last summer. This spring, the company is moving forward and what is now known as the Casa Diablo 4 Geothermal Development Project is undergoing environmental review. Earlier this week two public scoping meetings were held in the Eastern Sierra.

Three agencies — the Bureau of Land Management, the Inyo National Forest Service and the Great Basin Unified Air Pollution Control District — are involved in the environmental review process, with the BLM acting as the lead agency. Consulting firm, ESA ran the scoping meetings to familiarize the public with the project and to explain how comments on the project should be submitted.

ESA Senior Managing Associate Mike Manka explained the project as the firm understood it so far.

The project will run similarly to the three power plants the company already operates east of U.S. 395 and the Town of Mammoth. Construction would consist of a new power plant, new geothermal wells, pipelines and transmission lines to connect the energy to Southern California Edison’s (SCE) grid. Up to 16 wells are proposed, including the two that were drilled last summer.

Each well must sit on a well pad that will house the wellhead and a small control building. The well pad area is fenced in and when completed, consumes .4 acres of space. During drilling of the well, however, 2.5 acres of land is disturbed, Manka said. After drilling, each plot is rehabbed to only occupy the .4 acres.

This means that if the project is approved, there would potentially be up to 16, .4 acre well pads spread throughout the Shady Rest area. There could end up being less if Ormat finds certain wells that produce enough geothermal energy to power the plant, but there will not be more than 16, Manka explained.

In the beginning stages of a development such as this, when a company does not know exactly what it is going to find when it begins drilling, it asks for the maximum amount of wells it may need.

Water sources being proposed for the development include recycled water from the Mammoth Community Water District, as well as fluid from a reverse osmosis water treatment plant.

Manka was unsure how much new pipeline would be installed, but estimated approximately 2.5 miles, or about 13,000 feet.

In a follow-up email to Charlene Wardlow, Ormat’s Director of Business Development she confirmed that the project would install approximately 2.5 miles of new pipeline.

Public comments are due by May 9 for the scoping portion of the environmental review process. After comments are collected, public hearings are expected this summer to review draft environmental reports. According to Manka, the goal is to complete the environmental review process by early 2012 so that Ormat can begin development.

Written comments on the proposed Casa Diablo IV Geothermal Development Project may be submitted to the BLM Bishop Field Office, Attn: Casa Diablo IV Geothermal Development Project, 351 Pacu Lane, Suite 100, Bishop, CA 93514; or by email to; or by Fax to 760.872.5050.

For further information on the project or the scoping period, visit

Source: The Sheet News