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QTS Investment Properties Hillsboro, LLC

Air Toxics Health Risk Assessment Status

Cleaner Air Oregon is a health-based permitting program that regulates emissions of toxic air contaminants from facilities based on risk to nearby communities. CAO requires facilities to report toxic air contaminant emissions, assess potential health risks to people nearby and reduce toxic air contaminant risk if it exceeds legal limits.
As part of the Cleaner Air Oregon process, each facility has a dedicated web page to provide communities access to facility information and updates on where it is in the risk assessment process.
  • Each step of the CAO risk assessment process has a section that includes DEQ’s communications and deliverables from the facility.
  • For additional information and history of the program, visit Cleaner Air Oregon.

process diagram

​An Emissions Inventory is a list of each toxic air contaminant regulated under the Cleaner Air Oregon rules that a facility emits in a given year. The Emissions Inventory includes the amount of each toxic air contaminant emitted from each individual emissions-producing activity.
For an introduction to emissions inventories and why they matter, please see EPA’s Fact Sheet. A facility-specific emissions inventory timeline and associated documents are linked below.
Nov. 8, 2019: QTS submits Air Contaminant Discharge Permit Application to DEQ
Nov. 12, 2019: QTS provides revised Emissions Inventory
​A Modeling Protocol outlines parameters used in the dispersion modeling portion of the health risk assessment. This document identifies sensitive receptors at which risk will be assessed and outlines modeling parameters to be used in the facility’s dispersion modeling.
Nov. 8, 2019: QTS provides Level 1 modeling protocol.
  • QTS Modeling Protocol
  • A Level 1 risk assessment involves choosing dispersion factors from OAR 340-245-8050 Table 5 based on site-specific information. This includes stack height and distances to various Exposure Locations for stack emissions, and building height, dimensions, and distances to Exposure Locations for Fugitive emissions. A Risk Assessment Work Plan is not required in Level 1.
​Nov. 8, 2019: QTS submits Level 1 Risk Assessment
​Dec. 18, 2019: DEQ approves Level 1 Risk Assessment

About the Facility

QTS Investment Properties Hillsboro, LLC applied for a Standard Air Contaminant Discharge Permit for a prospective data center to be located at 4950 NE Huffman Street, Hillsboro, Oregon. QTS proposes to install four diesel-fired emergency generators each rated at 2,250 kilowatts of electric capacity.


Site Address

4950 NE Huffman Street,
Hillsboro, OR 97124

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