Porterville staff outline fire, water and drainage requirements for proposed 20,000 sq ft J & J Plastics warehouse in Airport Industrial Park

Porterville staff reviewed plans for a proposed 20,000-square-foot commercial warehouse for J & J Plastics at the end of Thunderbolt Drive (APN 302-390-019) in the Airport Industrial Park and identified a series of fire-safety, water and drainage requirements the applicant must address before construction permits can be issued.

Planning staff said the site is zoned Airport Industrial and within the Airport Overlay District and that setbacks and parking appear to meet the applicable sections of the development code. “The location of the building does meet setbacks. The parking area complying with section 304.10 of the development code,” Oscar Cepeda said.

Fire Marshal Clayton Dignam asked the applicant to identify the commodity stored, its hazard classification and amounts because the storage height (the application shows storage up to 16 feet high) triggers high-pile storage and influences sprinkler design and required fire flow. “What we’ll need is we’ll need the commodity identified specifically, the hazard classification of the commodity, and then the amount of that commodity,” Dignam said. He told the applicant that a sprinkler system will be required, fire extinguishers and a Knox box will be needed, and the sprinkler system must be designed to the appropriate standard for high-pile or commodity storage.

Dignam also said a 20-foot fire lane around the perimeter will likely be required (a 26-foot lane is required only for taller or different building configurations) and that hydrant spacing must be no more than 300 feet as a hose would lay. Because of the building length (the plan shows roughly 200 feet), staff said a looped water main with two points of connection and on-site hydrants will be required to meet the flow and spacing requirements. City staff noted an 8-inch water stub already exists on the property from earlier city improvements and that looping the line to the nearby city-owned cul-de-sac could provide the necessary redundancy.

Public-works staff said domestic, landscape and fire services must be protected by approved backflow devices; if a private fire-line connects to a private looped hydrant, certain shutoff valves (OS&Y) will require monitoring. Water-utility staff confirmed the city will require monitoring and periodic visual inspections where OS&Y valves are located on private property.

Engineering and fire staff discussed site drainage: the property currently drains westward to a city-built swale that eventually outlets to airport property. Staff said the swale was constructed during prior airport-industrial improvements and that paving and a b-gutter carry flow to the west; the applicant may need to preserve or reconstruct that swale with paved drainage. Engineering staff said a hardened (paved) 20-foot fire lane will be required for permanently maintained access; compacted crushed rock could be allowed only as a temporary construction-phase surface.

Staff also advised that the site will need underground plans, full sprinkler and underground-water plans, and that the applicant should expect standard requirements on turnarounds, radii and fire-lane marking. Staff noted prior plan-checks and permits from 2008–2010 exist for site improvements and recommended the applicant provide those prior grading and drainage plans to help inform current design.

City staff said they will compile departmental comments in a letter to the applicant within two to three weeks. No permit was approved at the meeting; staff provided preliminary technical requirements and asked the applicant to provide commodity details and updated engineering plans.