NC AWWA-WEA Fall Conference

November 18, 2014

Design and Construction Phasing of Large Wastewater Storage Lagoons for a Spray Irrigation Facility

• Case Study Introduction

• Design Constraints

• Design Solutions

• Conclusions

Overview

• Major Food and Beverage Manufacturer

• Generates up to 500,000 gpd wastewater

• Land applies pre-treated wastewater on 450 acre spray field system under permit

• Needed additional storage capacity for spray field management purposes.

Case Study: Irrigation Storage Lagoon Design

Original Wastewater Management System

Design Constraints

• Operational

• Horizontal Boundaries

• Vertical Boundaries

• Construction considerations

• Near by residents are concerned about potential for odors

•  Owner plans to operate the lagoon empty as often as possible.

• Some near by residents have been known to shoot at random objects for target practice.

•  The resulting process must be bullet proof (literally)

Operational Constraints (or “Living with your neighbors”)

•  If the lagoon is empty, it will be exposed to extremes of ambient temperature.

•  White liner material was selected to minimize temperature extremes.

•  If the lagoon is empty liner material will be subjected to potential wind uplift.

•  Liner must ballasted against wind uplift.

Considerations for operating the lagoon empty

• Must maintain overflow safety for pump station wet well at all times.

• Construction must be phased so that existing lagoon remains in service until new construction is in service.

• New storage lagoons must have capacity below overflow level

Operation During Construction

Horizontal Boundaries

•  [insert existing conditions plan]

Vertical Constraints

• Bottom of new lagoons below overflow of existing pump station overflow.

• Bottom of new lagoons above seasonal high water table.

• Top of berm below dam safety threshold

Construction Phase I

Construction Phase I

Construction Phase I

•  [add Phase I site plan]

Construction Phase II

Construction Phase II

•  [add Phase II site plan]

[insert hydraulic profile]

Construction Phase II

System Operation

A Working System

[insert photo of overlooking both lagoons]

[insert final hydraulic profile]

A working system

• Consider how the final system will be operated

• Consider vertical and horizontal boundaries

• Consider construction phasing

•  Importance of material selection

Conclusions

THANK YOU