Plan Review for Pumphouses

What do I need to include in a submittal of pumphouse plans and specifications?

• A scaled site plan showing the building outline, utility locations, site grading, and well location(s). It is recommended that a scale of one inch equals 50 feet be used.
• A scaled floor plan showing all piping and appurtenances with sizes labeled, treatment equipment, chemical injection points, and sample taps.
• An elevation drawing of the building showing the floor elevation at least 6-inches above the final surrounding grade elevation.
• Provisions for the well to pump to waste.
• A detailed diagram for each chemical feed system.
• A list of chemicals used for treatment, including manufacturer names and trade names.
• Chemical feed rates and size of rotameters.
• Provisions for chemical spill/leak containment for all chemicals.
• Mechanical plans showing equipment for plumbing, ventilation, heating and air conditioning, and dehumidification.
• Plumbing floor plans and riser diagrams showing all water supply and waste piping with sizes labeled, floor drains, venting, cleanouts, fixtures, water heater, valves, etc.
• Specifications for all equipment and materials, including manufacturer names and model numbers.

If a well is located within the pumphouse, what do I do about the building waste?

Since Minnesota Rules, chapter 4725 does not allow sewer pipe to be located within 50 feet of a community water supply well, building waste from a pumphouse with a well cannot be connected to a sanitary sewer system.  However, clear water drainage from floor drains may discharge to a buried gravel pocket that is located at least 20 feet away from the well.  If anything other than clear water drainage is generated, then another method of discharge or disposal must be provided, or a variance must be requested and approved by the Minnesota Department of Health.

Where do sample taps need to be installed?

A raw water sample tap must be provided prior to any chemical feed points or treatment equipment.  If the pumphouse has chemical feed or water treatment equipment, a sample tap shall be provided downstream from the final chemical injection point or treatment equipment.

When feeding polyphosphate for iron and manganese sequestration, where should it be injected?

Polyphosphate for sequestration of iron and manganese must be located as far upstream from any chlorine feed point as possible to ensure that sufficient time is provided for the reaction to go to completion.  It is recommended that a minimum of five feet be provided between these two injection points.