Uninterrupted Lift Station Operation Using By-Pass Pump

City of Oviedo

Utility – Wastewater Collection Division

April 2015

Uninterrupted Lift Station Operation

Emergency and/or

Uninterrupted lift

station pumping is

required by FDEP

(Chapter 62-604.400(2)(a)

62-604.400 Design/Performance Considerations

(2) (a) Emergency pumping capability shall be provided for all pump stations. Pumping capability shall be provided as follows:

1. Pump stations that receive flow from one or more pump stations through a force main or pump stations discharging through pipes 12 inches or larger shall provide for uninterrupted pumping capabilities, including an in-place emergency generator. 2. For pump stations not addressed in (2)(a)1. above, emergency pumping capability

may be accomplished by connection of the station to at least two independent utility substations, by providing a connection for portable or in-place engine-driven generating equipment, or by providing portable pumping equipment. 3. Such emergency standby systems shall have sufficient capacity to start up and

maintain the total rated running capacity of the station. Regardless of the type of emergency standby system provided, a riser from the force main with rapid connection capabilities and appropriate valving shall be provided for all pump stations to hook up portable pumps. All pump

station reliability design features shall be compatible with the available temporary service power generating and pumping equipment of the authority responsible for operation and maintenance of the collection/transmission system.

(

Typical Alternative Pumping Options:

Emergency Equipment

•Trailer pump or

•Trailer generator

Stationary Equipment

•Hard wired generator

•Hard plumbed by-pass pump

Advantages of Trailered Emergency equipment

Trailered emergency equipment is

• Cheaper (Less Capital expense)

• Works for multiple stations

• Labor intensive

Disadvantage of Trailered Emergency Equipment

Trailered Equipment requires

• Immediate 24hr/7day per week staff response

• Labor intensive set up for hoses or power cords

Uninterrupted Equipment

Stationary Generator

Stationary By-pass Pump

(FDEP requires repump or lift station with discharge of 12 inch or larger to have uninterrupted equipment)

Advantages of Stationary Generator

Stationary Generators • Use existing lift station pumps and controls

• Deigned to monitor grid and provide emergency

power to lift station when primary power falters

Disadvantage of Stationary Generators

Stationary Generators

• Most expensive option - Requires expensive

electrical isolation and switch gear equipment

• Dependent on lift station electrical equipment to

control pump start and stop.

• May require electrician to troubleshoot lift station

electrical issues.

• Requires generator to run the entire time power has

faltered

• Requires annual load bank testing

Stationary By-Pass Pump Oviedo has found an independent stationary By-Pass

Pump to be an economical and reliable option.

Simple System with Independent

Pump, Float Control & Motor Operation

Economic Advantage

City has found a typical By-Pass Pump System installation will cost about 30% less then a typical stationary generator system.

Capital Saving Example

No electrical switch gear required

Works Independently

The By-Pass Pump system is an independent system.

By-Pass pump system is not directly connected to lift station electrical and therefore isolated from typical lift station electrical Issues.

Lighting strikes,

Brown outs,

Power surges and

Electrical component failure.

62-604.400 Design/Performance

Considerations

• (2) (b) Pumping stations shall be protected

from lightning and transient voltage surges.

As a minimum, stations shall be equipped

with lightning arrestors, surge capacitors or

other similar protection devices, and phase protection

Ease of Operation By-Pass pump is simple to

operate:

• Small diesel motor

• Simple pump

• Independent start/stop: o Floats or

o Level indicator

By-Pass Pump Efficiency

By-Pass Pumps are efficient to Operate

• More fuel efficient, do not run under standby conditions. (On/Off with floats)

• Motor only operates pump

• Lift station staff can test in field by shutting down lift station

• No Load bank testing required

Typical

By-Pass Pump Installation Retrofit installation New Installation

By-Pass Pump Slab & Core

By-Pass Pump Plumbing

Other By-Pass Pump Advantages

• Pumps flows can be variable within ranges o Allows standard units to be shifted between different lift station sites

o Can be used for lift station rehab efforts

• Reduces point of failure part storage

Questions

City of Oviedo, FL

400 Alexandria Blvd. Oviedo FL 32765

Jim Woodger, Collection Supervisor 407-971-5690

jwoodger@cityofoviedo.net

Josef Grusauskas, Util. Manager 407-971-5679

jgrusauskas@cityofoviedo.net