Appeal 34948
Appeal Summary
Status: Decision Rendered
Appeal ID: 34948
Submission Date: 8/20/25 1:40 PM
Hearing Date: 8/27/25
Case #: M-1
Appeal Type: Mechanical
Project Type: commercial
Building/Business Name: Columbia Blvd. Wastewater Treatment Plant
Appeal Involves: Alteration of an existing structure
Proposed use: Add natural gas line to utilidor and enter underground tunnel through existing utilidor entry.
Project Address: 5001 N. Columbia Blvd
Appellant Name: Kelly Wood
LUR or Permit Application #: Preliminary
Stories: 0 Occupancy: F1 Construction Type: 1B
Fire Sprinklers: No
Plans Examiner/Inspector: None - no permit required.
Plan Submitted Option: pdf [File 1]
Payment Option: mail
Appeal Information Sheet
Appeal item 1
| Code Section | OMSC C404.6 |
|---|---|
| Requires | The mechanical code prohibits penetration of gas piping through building foundation walls below ground. |
| Code Modification or Alternate Requested | Allow the gas piping to enter an entirely below ground tunnel to a process facility through an existing utilidor. |
| Proposed Design | An existing concrete utilidor already enters the tunnel wall below ground, has space for a single, steel, natural gas pipe and can serve as means of conveyance into the underground tunnel. |
| Reason for alternative | An alternate is proposed for this wastewater process facility because the existing reinforced concrete structure (tunnel) is completely below ground, and an above grade penetration through the existing roofing system is impractical due to likely leakage by penetrating the roofing system that would cause corrosion of the reinforcing steel of the roofing structure. The existing below grade structure and utilidor structure have been in existence many years and are tied together structurally. The utilidor enters the structure through an existing wall. For additional safety, the 4” natural gas pipe is ASTM A53 steel and has an accessible isolation valve in the below grade structure for shutting off the natural gas supply if needed. The wastewater facility is staffed 24 hours per day, every day of the year, which allows for a fast response to any possible natural gas leaks. The tunnel is constructed of noncombustible materials, has ventilation that provides 6 air changes per hour, and contains both fire alarms and combustible gas detectors at the point of the tunnel where the utilidor enters. The existing gas piping in the tunnel also has drip traps. There is no piping material transition within the utilidor structure and an anodeless riser is installed for the steel to polyethylene buried piping transition prior to the utilidor. The penetration into the utilidor is sealed with grout and a modular elastomeric expanding seal to prevent gas leakage into the space in the event of a pipe break outside. |
Appeal Decision
Use of existing utilidor entry point for gas piping to boiler room in lieu of above ground entry point: Granted as proposed.
The Administrative Appeal Board finds that the information submitted by the appellant demonstrates that the approved modifications or alternate methods are consistent with the intent of the code; do not lessen the health, safety, accessibility, life, fire safety or structural requirements; and that special conditions unique to this project make strict application of those code sections impractical.