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ATTACHMENT K:INJECTION PROCEDURES Injection Pressures STIG-1 The injection initially indicated that the STIG-1 well injection rate of 100 gpm would require an injection pressure of approximately 210 psi and the maximum injection rate of 200 gpm would have an injection pressure of about 325 psi. Figure K-1 shows the relationship between injection pressure and injection rate for the operating data collected since 2000. This shows that overall,injection rates and pressures are consistent and do not show a direct relationship. Figure K-4 shows the historic injection pressure and measured well head pressures at the STIG-1 well. No overall increase in wellhead pressure has been seen over the operating period of the well. Experiences elsewhere suggest that those initial surface pressures will have to be increased gradually with time,in order to continue the fluids disposal at a constant flow rate. Then, after having performed appropriate downhole stimulation treatments (see Attachment J), the surface pressures can be returned to near-initial conditions. These same pressures are expected to be found on the new injection well. However,the operating permit does not allow the surface pressure be allowed to exceed 975 psi,which historic data show it has not. This is the recommended surface pressure limitation proposed after an extensive analysis was performed to determine the pressure required to initiate fracturing of the confining layer above the injection zone. For a detailed description of that analysis,refer to Section 10 of the Mesquite Report provided in Appendix 9 of this Application. LEC-1 and LEC-2 Pressure increases at the LEC-1 well (and LEC-2 well,if installed) are predicted to not exceed 800 psi over the 30 year life of the well (Figure K-5) Waste Streams The sources of the wastewater to be injected in each well are discussed below. The water quality of the injected wastewater was presented in Attachment H. STIG-1 Brine reject from the ultrafiltration units,brine from the reverse osmosis units, and blowdown from the cooling towers collectively comprise about 98 percent of the treated wastewaters that are injected. The other 2 percent of the liquid wastes intended for injection consist of both continuous and intermittent blowdowns from the Heat Recovery Boilers. No other waste streams are injected.Filtrate from the chamber filter press and multimedia filters are collected and routed back to the feedwater storage tank. Periodic effluent from cleaning the reverse osmosis membrane systems and de minimis losses collected in the Neutralization and Chemical Drain System are sent to the White Slough WPCF for treatment. Storm water, service water, and condensate and other liquids in the plant drains are collected separately,passed through an oil-water separator, and pumped to the White SAC/371322/082390003(ATTACHMENT-K.DOC) K-3