1. Project Overview Selective Catalytic Reduction Project Four Corners Power Plant Units 4 & 5 Arvin Trujillo Manager, Government Relations April 12, 2016

2. Topics What is the Selective Catalytic Reduction (SCR) Project? Project Timeline Economic Opportunities 2

3. What is the SCR Project? Remove more than 85% of the nitrous oxides (NOx) from the exhaust gas of Unit’s 4 and 5. SCR system comprised of new exhaust gas ductwork with which to inject ammonia that, with the help of a catalyst, will convert NOx to nitrogen and water.

4. Four Corners SCR Addition Video 4

5. What are the anticipated Ammonia needs by the SCR system? A new ammonia preparation system will also be required. This system will convert urea (ammonia fertilizer) to ammonia which is injected into the exhaust gas. About 20 trucks per week of dry urea will be required for both Units. – 19,000 tons of dry urea pellets/yr. A urea supplier will be needed. – Suppliers in IA, OK, and TX 5

6. 6 Project Timeline

7. Economic Opportunities During procurement and construction – AECOM has been hired to engineer, procure, and construct the SCR system – AECOM will subcontract much of the construction to companies like Sundt. – Upcoming Major Subcontracts: Painting, Electrical, Scaffolding, Insulation, Blacktop, Support Services, Inspection/Testing Services Significant labor recruiting efforts to date. – Sundt conducted job fair in Window Rock (800- 1000 people) – Sundt encouraging employment of Navajo Veterans 7