9582

• UCREFRP Catalog Number: 9582
• Author: U.S. Bureau of Reclamation.
• Title: Final Environmental Impact Statement - Navajo Reservoir Operations Volume III Comments and Responses.
• USFW Year: 2006.
• USFW - Doc Type: Grand Junction - Durango, CO.
• Copyright Material: NO

Volume III - Comments and Responses
FEIS - Navajo Reservoir Operations
contaminants would also be identified, and a program to reduce the loading would be
implemented. This regulatory process has been set up by the EPA; Reclamation does not
have regulatory control of water quality pollutants or programs.
As identified in the EIS, the San Juan River reach from Navajo Dam to Farmington would be
most affected by any decrease in flows. Concentrations of several water quality parameters
would increase, and exceedences could occur more often than historical data indicate. Fecal
coliform is listed as one of the parameters on the State's 303(d) list for the river segment
from the Highway 64 Bridge in Blanco to the confluence of the San Juan and Animas Rivers.
Fecal coliform has exceeded the standards enough times that the State placed it on the
Section 303(d) list. The State is in the process of evaluating whether or not a TMDL will be
determined. The Section 303(d) list also states it is not an acute public health concern. If a
TMDL is determined, a program will be developed to identify and lower sources of this
pollutant.
The municipal sewage treatment plant's discharge permit at Bloomfield could be impacted
by changes in flow. Some improvements to the Bloomfield plant have been made in
anticipation of stricter New Mexico water quality standards.
Concerning the treatment of raw water for drinking purposes, in general, the water quality
of the mainstem of the San Juan River is good. Historical data indicate most parameters do
not exceed State or Tribal standards. Water quality studies from future projects indicate the
number of exceedences will continue near the present number. Water quality in the river
will continue to be monitored and evaluated by Federal, Tribal, and State agencies. For
example, the Bureau of Land Management monitors the San Juan River for polycyclic
aromatic hydrocarbons (PAHs) and has found little indication that PAHs are present at
significant levels in the river. No mitigation for water quality is planned.
The Preferred Alternative may have an impact on the cost of treating water for human
consumption. Communities that derive their drinking water from the San Juan River above
Farmington include Navajo Dam, Blanco, Turley, Lee Acres, and West Hammond.
Reclamation representatives contacted managers at the Blanco Water Users Association
(BWUA), Navajo Dam Water Users Association (NDWUA), and West Hammond Domestic
Water Association (WHDWA) to determine the potential for the magnitude of this impact.
During these discussions, it became apparent that there could be an increased cost to treat
water because of a reduction in the dilution rate when releases from Navajo Dam are
lowered to 250 cfs.
Water treatment issues of greatest concern are E. coli and turbidity. The increased rate of
their occurrence is directly related to runoff from storm events, especially during spring and
summer months, when storm events flush contaminants into the river. These contaminants