San Juan Generating Station
- San Juan Generating Station uses an average of 22,000
of water acre-feet per year.
- San Juan has rights to 24,200 acre-feet per year
16,200 acre-feet from the Navajo Dam reservoir through a
Bureau of Reclamation contract and 8,000 acre-feet in native
stream flow from the San Juan River through a contract with
- Water is used at San Juan for cooling systems and cleaning
of equipment and facilities. The plant has cooling towers
that condense the steam used in the turbine back into water
so it can be reused. Through a series of complex processes,
water is reused, at least 10 times and as many as 50 to
100 times before it evaporates.
- Unit 3 at San Juan has a "hybrid" cooling tower
one that can run in both wet and dry modes. Unfortunately,
this unit has not performed as well as the wet cooling tower
units. Engineering estimates indicate that converting the
plant to dry cooling could add at least 10 percent to the
cost of electricity production because of lower energy efficiency
and increased construction and maintenance costs. Because
of the "energy penalty" thus imposed, the amount
of emissions per megawatt produced will also increase with
the use of dry cooling.
- San Juan is a "zero discharge" facility, meaning
no wastewater is discharged to either the San Juan River
or underground water supplies.
PNM's efforts to secure short-term supplemental water supply
and the San Juan Basin shortage sharing recommendations:
- Due to drought conditions in the Four Corners area and
at the suggestion of the state engineer and the Bureau of
Reclamation, PNM and 12 other parties in the Four Corners
region were encouraged to develop a voluntary shared shortage
water plan based on reasonable use to address anticipated
shortages this year.
- Starting in the fall of 2002, the Navajo Nation, the Jicarilla
Apache Nation and the other entities including PNM, Arizona
Public Service Co., owner and operator of the Four Corners
Power Plant, and BHP Billiton, owner and operator of the
Navajo, San Juan and La Plata mines, began negotiations
on recommendations to address the potential summer water
shortage and resulting usage issues.
- Principles and recommendations were developed that all
13 parties agreed upon. These recommendations were finalized
in May 2003 and were accepted by the state engineer and
the Bureau of Reclamation.
- This shortage sharing arrangement is an unprecedented
example of tribal, governmental, agricultural and industrial
water users in the Four Corners region working together
to establish water priorities and address shortage issues
without litigation and prior to a more serious situation
- In connection with the shortage sharing arrangement, PNM
also entered into a contract to purchase water from the
Jicarilla Apache Nation for use at San Juan. This contract
has received final approval by the Bureau of Reclamation
and the U.S. Fish and Wildlife Service. The one-year contract,
with two one-year renewal clauses, will allow San Juan Generating
Station access to an additional 8,300 acre-feet of Navajo
Reservoir water during shortage time periods.
- PNM, Arizona Public Service and the mines are currently
taking shortages based on recent drought calculations. PNM
has paid the Jicarilla Apache Nation $80,000 for the first
10 percent of the allocation.