WSP10769

• File Number: 8220.105
• Description: Colorado River-Water Projects-Navajo
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 7/1/2001
• Author: BOR
• Title: Revised Draft Environmental Assessment for the Jicarilla Apache Nation Water Subcontract-aka USBR/PNM Water Contract Renewal and Extension
• Water Supply Pro - Doc Type: Report/Study

I

I

I

contained in the limestone. Briefly, the process involves spraying the reactive slurry into the gas stream.
The SO, in the gas stream reacts with the water and calcium carbonate, forming solid particles of calcium
sulfite and calcium sulfate. With the addition of oxygen, the calcium sulfite is force oxidized to calcium
sulfate. These particles are constantly removed in the form of waste slurry. Supporting systems to prepare
and feed fresh limestone slurry, thicken and dewater the waste slurry, and disposalpfthe solid waste are
piv'\"id~d, ilt:ii.ilt;lIg ili it lUli11 FGD :,y~it::lII. Tilt: FGD system is designed to scrub up to 100 percent of the
flue gas. although bypass capability is necessary due to boiler and electrostatic precipitator (ESP) design.

I

I

The FGD system includes: limestone handling system, absorbent preparation system, absorber system,
primary and secondary dewatering system, and gypsum handling system.

6,1.2 Current Information on .Emissions

I
I

Table 2 summarizes the SJGS air emission limits.

6,1.3 Impacts of the Proposed Action

I

Under the proposed action, air emissions by the SJGS would continue subject to current and future federal
and state air quality regulations and standards, through the projected life-of-plant. SJGS is in compliance
with the terms and conditions of all applicable air regulations. SGJS has.not had a particulate emissions
notice of violation (NOV) since 1985 brought on by mechanical difficulties with the Unit 4 precipitator.
These difficulties were repaired, retested. and SJGS has demonstrated compliance ever since.

I

6.1.4 Impact of the No Action Alternative

I

If the proposed action is not implemented and ifPNM is unable to acquire sufficient alternative water
supplies to allow it to continue to operate SJGS, operations at SJGS would cease. Under this scenario,
emissions of SO" NO" and particulates would cease and air quality could correspondingly improve from
the cessation of those emissions.

I

6.1.5 Mitigation Measures for the Proposed Action Alternative

I

Air pollution control equipment has already been installed at SJGS that allows the plant to continue to
meet applicable federal and state air emission standards.

I
I

6.2 HydrologylWater Quality/Sediment Quality

I

The operation of the SJGS and ancillary facilities theoretically could have the potential to affect the San
Juan River. a large perennial stream upon which the SJGS relies for its water supply, and Shumway
Arroyo and its tributary, Westwater Arroyo. Shumway Arroyo discharges into the San Juan River from
the north approximately 4.5 miles downstream of the pump station.

The San Juan River is characterized by large spring snowmelt peak flows, low summer and winter base
flows, and high magnitude, short duration summer and fall storms. The completion of Navajo Dam in
1963 reduced the spring snowmelt peak by about 50 percent and increased the base flow during the
months of August through February by about 170 percent. Minimum flows were also elevated, and near-

I

t5

O ~ 1. n
U J ;1'.