County of Imperial

Air Pollution Control District Hearing Board

Wednesday, July 9, 2025 at 12:00 p.m.

NOTICE IS HEREBY GIVEN that a public hearing will be held on Wednesday, July 9, 2025 at 12:00 pm at the Imperial County Air Pollution Control District (ICAPCD) located at 150 South 9^th St., El Centro, CA 92243. The purpose of this hearing is to consider a request by Hudson Ranch Power I, LLC, for their geothermal power plant facility located at 409 W. McDonald Road in Calipatria, CA, for a Regular Variance (03-25REG). The requested Regular Variance is for Permit Conditions 11, 12, 13, and 14 of Permit to Operate (PTO) No. 4233A, which pertain to the nitrogen oxides (NOx) emission limits and source test requirements of three emergency generators at the facility. The Permit Conditions are listed below: 

 

11.      The diesel engine of each black start emergency generator shall not exceed the emission limit of 28.58 pounds per hour of NOx emissions.

 

12.      The diesel engine of the emergency standby generator shall not exceed the emission limit of 11.93 pounds per hour of NOx emissions.

 

13.      The diesel engine of each listed black start emergency generator shall be source tested for compliance with the emission limits of Condition 11 within the first 60 days of installation and every three (3) years thereafter. The frequency of source testing may be extended to not less than every 60 months for each black start emergency generator under the following conditions:

 

a.        Each black start generator operates less than 500 hours per 12 month period (as demonstrated by operational logs) and which emit less than 5 tons of NOx per 12 month period. This period may be extended if a source can prove that the each black start generator has not been operated during the calendar year.

 

b.        Each black start generator uses a portable NOx analyzer to take a NOx emission reading to verify compliance with Condition 11 during each quarter in which a source test is not performed. The portable analyzer shall be calibrated and used per Air District Rule 400.3.G.2.b.

 

14.      The diesel engine of the listed emergency standby generator set shall be source tested for compliance with the emission limits of Condition 12 within the first 60 days of installation and every three (3) years thereafter. The frequency of source testing may be extended to not less than every 60 months for the listed emergency generator under the following conditions:

 

a.        The emergency generator operates less than 500 hours per 12 month period (as demonstrated by operational logs) and which emit less than 5 tons of NOx per 12 month period. This period may be extended if a source can prove that the unit has not been operated during the calendar year.

 

b.        The emergency generator uses a portable NOx analyzer to take a NOx emission reading to verify compliance with Condition 12 during each quarter in which a source test is not performed. The portable analyzer shall be calibrated and used per Air District Rule 400.3.G.2.b.

 

Documentation in support of this request is on file at the ICAPCD office, located at 150 South 9^th St., El Centro, CA 92243.

 

All interested persons desiring to present evidence on this term may appear at the hearing, and upon being sworn, may provide testimony. For additional information, contact the ICAPCD at 442-265-1800.

THE HEARING BOARD OF THE

IMPERIAL COUNTY AIR POLLUTION

CONTROL DISTRICT

By: Cassi Justice

Clerk of the Hearing Board

Date: June 17, 2025