Comments on: Hazardous Area Classification for Pumping Stations

By: Michael White

Michael White — Thu, 20 Jan 2011 21:50:07 +0000

The scope and definitions in 820 are ambiguous about what is considered a “collection system” or “collection facilities”. I do not believe that 820 was intended to apply to stormwater collection systems or facilities that DO NOT feed into wastewater treatment systems or facilities. A typical facility that should not fall under 820 would be something like a pump plant that collects stormwater only from a roadway and discharges it to a stormwater system that does not flow to a wastewater treatment facility. This ambiguity is causing many municipalities to waste money to get a minimal reduction in a risk that may never be realized.
I would like to hear opinions of others in the industry about the applicability of NFPA 820. Tight budgets should force us back to making sound engineering decisions instead of ones based on excessive safety merely to avoid a lawsuit.

By: Pat Coleman

Pat Coleman — Mon, 10 Jan 2011 04:08:18 +0000

How do you normally handle the reuirement for 30 ac/hr when the wet well is not ventilated (as per 10 states)? Do you know the history of thsi requirement?

From 10 States Standards (2004)

42.75 Wet Wells

Wet well ventilation may be either continuous or intermittent. Ventilation, if continuous, shall provide at least 12 complete air changes per hour; if intermittent, at least 30 complete air changes per hour. Air shall be forced into the wet well by mechanical means rather than solely exhausted from the wet well. The air change requirements shall be based on 100 percent fresh air. Portable ventilation equipment shall be provided for use at submersible pump stations and wet wells with no permanently installed ventilation equipment.

By: saleem

saleem — Thu, 06 Jan 2011 06:13:37 +0000

Pl provide hazardous areas name for different process services of pumps