Dear Editor, I have just read the Letter to the Editor about the Parsa pumped storage project in Israel, on p10 of the April 2001 issue. I have a strong interest in this project as it intends to use treated sewage water instead of the usual fresh river water.

I expect that the project manager is concerned about the corrosion of hydro mechanical equipment, as well as environmental contamination surrounding the reservoirs.

At the Electric Power Development Company (EPDC) we constructed the Okinawa seawater pumped storage plant in Japan. Since commissioning in March 1999 we have had a good operating record. At this project we introduced many new and improved technologies to counter the strong corrosion of seawater, as well as to avoid contamination of underground water near the upper pond. (For more details on the Okinawa project see IWP&DC March 1998, pp28-29; and August 2000, pp30-34).

EPDC is one of the most experienced consultants for pumped storage. We own and operate eight pumped storage plants totalling 4987MW in Japan, and have provided consulting services for nine projects totalling 7400MW worldwide. If the project manager at Parsa experiences similar problems to those at Okinawa pumped storage plant, I believe that we can provide some useful information and advice.