Construction Dewatering

At Griffin, our expertise is in groundwater controlfor challenging construction projects and subsurfaceconditions. Griffin specializes in dewatering and groundwater control, utilizing such techniques as eductors, deep wells, wellpoints, slurry walls, and relief wells.

What Is Dewatering? Dewatering means

“the separation of water from the soil,” or perhaps “taking the water out of the particular construction problem completely.”

This leads to concepts like pre-drainage of soil, control of ground water, and even the improvement of physical properties of soil.

Controls ground water, and even the improvement of physical properties of soil.

Intercepts Seepage

Achieves waterproofing objectives

What Does Dewatering Do?

Origins Of Dewatering

Human efforts to control water predate recorded history.The first practical wellpoint dewatering system in the U.S. was used in Hackensack, NJ in 1925.

Excavation Support Systems Rendered Unstable

Future Settling

Lost Time

Decreased Worksite Safety

Increased Cost

ConsequencesOf ImproperDewatering

Dewatering Methods

Wellpoint SystemA wellpoint system consists of a number of wellpoints spaced along a trench or around an excavation site, all connected to a common header, which is attached to one or more wellpoint pumps.

Wellpoint systems are most suitable in shallow aquifers where the water level needs to be lowered no more than 15 or 20 feet. Due to the vacuum limitation of the pump, excavations that are deeper will require multiple stages of wellpoint systems.

Deep Well SystemDeep well systems consist of one or more individual wells, each of which has its own submersible pump at the bottom of the well. Deep well systems are suitable for water-table or confined aquifers and will lower the water table 100 feet or more in a single lift without staging.

Eductor SystemThe eductor system is generally used in areas where the soils have a low permeability. It is especially well suited for deep excavations with stratified soils. The eductors are installed at relatively close spacing similar to the array in wellpoint systems, but require only a single stage to effect draw downs of up to 100 + feet.

Open Pumping

Axial flow pumps on a temporary pump station was capable of pumping 200,000 gallons per minute (gpm) with a standby capacity of 30,000 gpm.

The removal of water from a site or an area commonly called; sumping, unwatering, or open pumping.

Temporary & Permanent Dewatering Systems

Intercept Seepage

Improve the excavation and the backfill characteristics of the excavation to allowconstruction to proceed in a safe and efficient manner.

Achieve waterproofing objectives.

Reduce or eliminate lateral and/or uplift pressures.

PermanentPermanentTemporary

Details Of A Dewatering System

Considerations When Selecting A Dewatering

System

Size & Depth Of The Excavation

Location And Environment

Proximity Of Existing Structures

Existence Of Any Contamination

Soil Characteristics AndSubsurface Conditions

Aquifer composition and distribution

Hydraulic conductivity, transmissivity, storage coefficient

Flow rate calculation for proposed construction area to be dewatered

Aquifer Characteristics

Construction Schedule

Time always equals money in construction

How does the Dewatering System impact the budget and schedule?

The Dewatering system should be a long term asset for ongoing operations

Dewatering Case Studies

The dam’s construction method comprises its problem- the sluiced fill materials. Thismaterial has a loose (or very loose) relative density. Consequently, the dam is susceptible toliquefaction during an earthquake.

Need for Renovation

Saluda Dam RemediationCase Study

Griffin installed Deepwells, Eductors, & Wellpoints on downstream toe of dam for excavation of up to 80ft. in depth.

Saluda Dam RemediationCase Study

The project was a significant undertaking. In addition to keeping the 48,000 acre reservoir nearly full, which is rimmed with businesses and houses, and keeping the hydroelectric plant and coal fired steam plant operational, the project also required that we ensure the safety of the 120,000 residents living in the flood plain downstream in Columbia, SC. All the above was required, while also addressing the environmental concerns regarding the wetlands encircling the Saluda Dam.

Owner: SCE&G – Columbia, SC

General Contractor: Paul C. Rizzo Associates, Monroeville, PA

Specialty Sub Contractor: Griffin Dewatering

Batchtown Wildlife RefugeCase Study

Griffin deep wells installed on a oval earthen berm directly in the Mississippi River

A deep well dewatering system for the Batchtown Wildlife Refuge Rehabilitation project near St. Louis, Missouri. The wells were installed on a oval earthen berm directly in the Mississippi River. Individual wells were pumping roughly 1750 gallons per minute each.

Building Team/Key Players: Army Corp of Engineers, US Fish and Wildlife Service,Griffin Dewatering North Central, LLC

Case Study

Deep well dewatering system in operation atan excavation near the Mississippi River

A deep well installed at an excavation for a pumping station being built in New Madrid Missouri in close proximity to the Mississippi river for the Army Corps of Engineers.

Building Team/Key Players: Army Corp of Engineers: Memphis District, Hill Brothers Construction & Engineering Co., Griffin Dewatering Southwest

New Madrid Pump Station

Installation of high volume deepwells for excavation 51ft. below high Mississippi River elevation.

Case Study

Riverpoint West Street Improvement project

Sewerline installation located in Des Moines, IA This photo depicts an

excavation in Des Moines, Iowa of a 30 foot deep sewerline installation located 3 feet above the bedrock. Deep dewatering wells were used to lower the groundwater 8 feet and a 600 foot long, 200 point wellpoint system was installed 17 feet below existing grade to handle the rest of the groundwater.

Building Team/Key Players: J&K Contracting General Contractor – Ames, IA,Griffin Dewatering North Central, LLC Sub Contractor – Omaha, NE

Case Study

Pearland Town Center - Detention Pond

Building Team/Key Players: EMJ Construction General Contractor – Chattanooga, TN,Griffin Dewatering Southwest, LLC Sub Contractor – Houston, TX

A Wellpoint System was used for the construction of a detention pond at the Pearland Town Center in Pearland, Texas

Case Study

Crystal River Power Plant Expansion

Installation of high volume sumping equipment forexcavation into Florida limestone formations.

General Contractor:Zachary Construction

Specialty Sub-Contractor:Griffin Dewatering

Case Study

Lake Fork Pumping Station

Installation of deepwells and wellpoints for +65ft excavation.

The Lake Fork Pump Station project was constructed by Bar Constructors. Lake Fork is the first new water source connected to the DWU raw water system in 40 years. The Lake Fork Pump Station is a 240 MGD raw water pump station located approximately 95 miles east of Dallas on Lake Fork.

General Contractor:Bar Constructors

Specialty Sub-Contractor:Griffin Dewatering

Case Study

El Cajon Public Safety Center

This construction project is located in the County of San Diego for the city of El Cajon. The dewatering system on this excavation consists of a dewatering system installed around the perimeter of the excavation. It consists of a series of electric submersible pumps installed inside of deep wells by Griffin Dewatering Farwest.

General Contractor:Ledcor Construction Inc.

Specialty Sub-Contractor:Griffin Dewatering Farwest

Location:El Cajon, CA (San Diego County)

Case Study

Galena River Bypass

The pump in the foreground is a 12” Non-Clog pump for bypass pumping of the Galena River around an excavation for a new railroad bridge. The pump in the middle was a high pressure 6” pump used to install the wick points. The pump in the foreground is an 8” Non-Clog Variable Use Pump for the wick point dewatering system.

General Contractor:Rieth-Riley Construction

Specialty Sub-Contractor:Griffin Dewatering Midwest

Location:LaPorte County, Indiana

Case Study

Lake Isabella Bypass

Griffin axial flow pumps on Lake Isabella. Fed by the Kern River, the lake is a primary source of water for farmers in the southern part of the largest agricultural area in California. Griffin Dewatering Corporation was called in to design, construct, and operate a temporary pump station that would run for five months. The station was capable of pumping 200,000 gallons per minute (gpm) with a standby capacity of 30,000 gpm. The quantity the station actually pumped was dependent upon the demand downstream.Location: High in the desert mountains

above Bakersfield, California and San Joaquin Valley.

General Contractor: Griffin Dewatering Farwest

Owner: Isabella Partners

Case Study

Prado Dam Embankment and Outlet Works

General Contractor: Doty Brothers Equipment Company

Owner: U.S. Army Corps of Engineers, Los Angeles District

Sub Contractor: Griffin Dewatering FarwestLocation: Dam on the Santa Ana River in Riverside County, California

Griffin Bypass equipment installation. Prado Dam sewer bypass pumping at 22 million gallons per day located in Santa Ana River near Corona, California.

Temporary bypass systems are used to transfer water supplies and sewage flow, so that vital services are uninterrupted during construction.

Case Study

General Contractor: Olsson Construction Inc.Owner: Orange County Sanitation District

Sub Contractor: Griffin Dewatering FarwestLocation: Costa Mesa, California

At the heart of the bypass at the Olsson Construction Inc. Westside Pump Station job are these two 16” vacuum assisted non clog pumps, fitted with 100hp electric motors. Two 10” diesel powered, vacuum assisted non clog pumps are also installed, as back up for the system. Fitting this many large pumps into the very small space allotted was difficult; however, Griffin’s field crew did an excellent job.

College Avenue Pump Station

Case Study

General Contractor: Judds Brothers ConstructionOwner: City of Iowa City, The Public Works DepartmentSub Contractor: Griffin Dewatering North Central Location: Iowa City, Iowa

The project is the replacment of a siphon sewer under the Iowa River. Griffin is bypassing the sewage from the old structures while the new sewer connections are made. Total volume is about 6,300 gallons per minute. Total duration of the job is 2 weeks from startup to shut down of the new 18 inch non-clog pumps. Griffin is bypassing sewage from 3 different locations on site and 2 operate at any one time.

Siphon Sewer - Iowa City

General Contractor: Linbeck ConstructionOwner: Rice University

Sub Contractor: Griffin Dewatering SouthwestLocation: Houston, Texas

Case Study

Rice University Collaborative Research Center

The project (CRC Rice University) consists of a ten story building next to the Rice University Campus inside of Houston Medical Center. Griffin installed a 1400 linear foot eductor system to lower the groundwater below the deepest cut (40 feet deep from the street level). These eductors are 65 to 80 feet deep and drilled outside the excavation area along the property line. The eductor system with two pump stations has lowered groundwater more than 5 feet below the deepest excavation.

Case Study

Installing 10 Deep Wells Up To 60 Feet Deep

GC: Granite/Traylor/Frontier-Kemper

Owner: NYC Metro Transportation Authority

Sub: Griffin Dewatering New England

Location: Queens, NY

Eastside Access Queens Bored Tunnels

Case Study

Love Field Airport Modernization

GC: Hensel Phelps Construction Co.

Owner: Southwest Airlines, Dallas

Sub: Griffin Dewatering Southwest

Location: Dallas, TX

Installed 7 Deep Wells and 70 Wickpoints on Concourse Area and 20 Deep Wells in the Ticketing Area