Miami-Dade Water & Sewer Department

Miami-Dade Water and Sewer Department | www.miamidade.gov/water

February 25, 2016

Nutrient Reduction by Use of Industrial Deep Injection Wells,

Miami-Dade County, Florida

Virginia Walsh, PhD, P.G.Ed Rectenwald, P.G.

Miami-Dade Water and Sewer Department (WASD) Overview

• Largest water and sewer utility in Florida, serving more than

2.2 million residents

• Water System:

3 large regional and 5 small water treatment plants

Supplying an average of 304 million gallons per day

90% of the County’s public water supply

Per capita water use 137 gpcd

100 water supply wells

Biscayne Aquifer

Floridan Aquifer

Aquifer Storage and Recovery

7,918 miles of pipes (12.740 km)

38,381 fire hydrants

126,913 valves

WASD Overview

• Wastewater System:

3 wastewater treatment plants

2 ocean outfalls (3 and 7 miles from

coast) and 21 deep injection wells

(~2,500 ft depth)

Collecting, treating, and disposing 316

MGD

6,292 miles of mains and laterals

1,042 sewer pumps stations (operated)

Reusing 10.2 MGD

WASD Water & WastewaterTreatment Facilities

Ocean Outfalls

Deep injection

wells

2008 Ocean Outfall LegislationChapter 2008-232, Laws of Florida

• Reduce nutrient loading to the ocean

Meet Advance Wastewater Treatment (AWT) by Dec 31, 2018, or

Reduce cumulative outfall loadings (from 2008-2025) equivalent to AWT from 2018-2025

• December 31, 2025, stop using outfall and implement 60% reuse

EPA

2005

Underground Injection Control Program—Revision to the Federal Underground

Injection Control Required for Class I Municipal Disposal Wells in Florida

(40 CFR Part 146 [FRL-7999-7]).

Requirement for High Level Disinfection(HLD) treatment facilities to be added atthe South District Wastewater TreatmentPlant (SDWWTP).

An HLD facility is required before a permit for theconstruction of any new Class I municipal injectionwells can be issued in South Florida, includingMiami-Dade County.

Anhydrite confining units(not carbonate units)

Current deep

injection well Boulder Zone (within

the FAS)

Potential disposal zones within fractured interval

(not in the FAS)

Exploratory Well Objectives

• Permit as a Class V Exploratory Well

• Perform Standard and Petrophysical Geophysical Logs, Testing, and Coring

• Analyze for sufficient confinement above the Boulder Zone

• Analyze the sub-Floridan confinement above the permeable Cretaceous Formations

• Analyze for adequate injection zone within Cretaceous Formations to approximately 10,000 feet bls

• Complete injection well within the Boulder Zone, Permit as Class I Industrial with Dual-Zone Monitor Well

• Preliminary Evaluation and Site Characterization for future disposal into the permeable Cretaceous Formations Reduce nutrient

loading

Virginia Key Landfill

Interdepartmental Agreement with Miami-Dade Water and Sewer and Public Works and

Waste Management to dispose of groundwater remediation

leachate into adjacent Central District Plant Deep Injection

Wells

USGS Carbonate Aquifer Characterization LaboratoryDavie, FL

Preliminary seismic studies

at Virginia Key in collaboration

with USGS prior to drilling

Seismic profiling at CDWWTP

Miami-Dade County

USGS PROVISIONAL DO NOT CITE

Central District Wastewater Treatment PlantVirginia Key

CDWWTP IW-1 Class V Injection Well Design

10,000’

Sub-FloridanConfinement Zone

Potential Injection Zone

10000

9200

8800

8400

8000

7600

7200

6800

6400

5600

5200

4800

4400

4000

3600

3200

2800

2400

2000

1600

1200

800

400

0

6000

9600

Base of USDWat 1,360’ bls

Boulder Zone

3,150’

2,780’

Well IW-1 Actual Casing Depths to Date

• 74-inch Steel to 73 feet bls• 66-inch Steel to 300 feet bls• 56-inch Steel to 1,060 feet bls• 46-inch Steel to 2,090 feet bls• 36-inch Steel to 2,780 feet bls

Well IW-1 Anticipated Casing Depths• 24-inch FRP to 2,780 feet bls

Well IW-1 Injection Zone• 2,780 feet to 3,150 feet bls

Permitted injection capacity is 19.9MGD

• ~1 MGD Centrate• ~12 MGD Scrubber Blowdown• ~5 MGD Effluent• ~1 MGD Leachate

Youngquist Brothers Incorporated (YBI)E-Rig Series Electric Drilling Rig

• SAFETY-CENTRIC JOB SITE (WELL CAP TRAINING, H2S

TRAINING, CPR/FIRST AID TRAINING)

• API RATED ELECTRIC DRILL RIG WITH MAX RATED

HOOKLOAD OF – 1,086,000 LBS.

• 140’ TALL DERRICK + 16’ SUBSTRUCTURE

• 16’ SUBSTRUCTURE DESIGNED/ENGINEERED TO

ACCOMMODATE 5000 PSI BOP AND WEIGHT OF

RIG/LOAD

• REDUNDANT BOP OPERATION/CONTROL WITH ELECTRIC

AND DIESEL OPTIONS.

• RACKING BOARD DESIGNED/ENGINEERED TO RACK

10,000’ OF 7” DRILL PIPE

• PORTABLE SUBSTATION TIES IN DIRECTLY TO UTILITY

PRIMARY POWER FOR CLEAN ENERGY.

• 1500 HP DRAWWORKS

Youngquist Brothers Incorporated (YBI)5,000 PSI Rated Blowout Preventer (BOP)

• API and HSE Certification

• 13 5/8” Annular BOP

• 13 5/8” Double Ram with Shear Rams

• BOP Control System

Large Diameter Boreholes

• Largest diameter borehole (46-inches) in Florida to a depth of 2,780 feet bls

CementingLarge diameter mudded borehole

• 66 inch diameter borehole to 1,070 ft BLS

Pilot hole vs. Reamed hole

• 15 stages to back plug pilot hole from 3,500 ft BLS

• 56 stages to cement in 36 in steel casing from 2,780 ft BLS

Lithologic Descriptions, Core Analysis, Geophysical Logging, Packer Testing

Permeability within Cretaceous Aged FormationComplex Injection Capacity Evaluations

• Permeability/Transmissivity

• Fractures/Fissures

• Geochemistry– Injection zone TDS could be

300,000 mg/L

– Injectate TDS will be 1,000 mg/L.

– Need to properly analyze buoyancy effects in testing data sets.

• Goal is to predict injection capacity and wellhead pressure.

Cretaceous Geology

Text Book Anhydrite

Bulk Density = 2.96 gm/cc

Pe = 5

Cretaceous Permeable Units

$2.5 billion in HLD costs to comply with the Ocean Outfall Legislation

24 inch: 26/30

30 inch:19/22

Analysis to determine injection to Cretaceous formations cost effective vs traditional disposal zones

Determination of suitable sites for additional Class I Industrial Waste Wells

Questions?

For further project or technical information contact:

Virginia Walshwalshv@miamidade.gov

and

Ed Rectenwaldedward.rectenwald@mwhglobal.com

$1.2 billion for HLD facilities at existing facilities$1.3 billion for new HLD West District Wastewater

Treatment Plant____________________________

$2.5 billion in HLD costs to comply with the Ocean Outfall Legislation

CDWWTPTreatment/Disposal MethodHLD PlantBoulder Zone Injection WellsTotal for HLD w/Boulder Zone injection wells

NDWWTP*HLDBoulder Zone Injection WellsTotal for HLD w/Boulder Zone injection wells

Total WASD System Wide

CDWWTP/NDWWTP HLD and Wells

Presentation Outline

•Overview

•Objectives

•Preliminary Investigations

•Technical Design

•Construction Activities

Compliance with Ocean Outfall Legislation

If build AWTfor nutrient

removal 2018:

• Reduce nutrient loading to the ocean

Meet Advance Wastewater Treatment (AWT) by Dec 31, 2018, or

Reduce cumulative outfall loadings (from 2008-2025) equivalent to AWT from 2018-2025

• December 31, 2025, stop using outfall and implement 60% reuse

Centrate Deep injection well 2017:

60,015,437 lbs

59,874,077 lbs

Miami-Dade

CDWWTP

Injection Well

Rebecca Shoal ReefPossible permeable zones for injection

Documented Deep Geology Caverns in Miami-Dade County

Well 41

Well 6

Well 52

Central District WWTP

Geophysical Logging

• Dipole Shear Sonic

• Nuclear Magnetic Resonance

• Formation Microimager

• Neutron Porosity

• Optical Borehole Imaging

• Petroleum industry logs for

analysis of mineral and

porosity

Packer Testing

• Obtain discrete water quality data

• Validate log-derived results

• Estimate confinement properties

• Target monitor zones

Complex Injection Capacity Evaluations

• Need to understand buoyancy effects during testing.

• Injection zone TDS could be 300,000 mg/L

• Injectate TDS will be 1,000 mg/L.

• Need to properly analyze buoyancy effects in testing data sets.

• Goal is to predict injection capacity and wellhead pressure.

Formation Plugging and Precipitation Analysis

Chemical Characteristics - Desktop Evaluation

• Preliminary Blended Waste Stream Evaluation

• Preliminary Blending of Combined Waste Stream with Groundwater

StruviteNH4MgPO4·6H2

BlendingScenario 1

BlendingScenario 2

Parameters mg /L mg /L

pH 6.77 6.41

Ammonia-N 43.26 21.94

Magnesium 66.85 67.10

Total P 3.39 1.92

Struvite Saturation Index 0.006096 0.0004909

Precipitation and Plugging Potential - Bench Scale TestsBlended waste streams Blended injectate with ambient aquifer water of injection zone

Blended Wastestream• ~1 MGD Centrate• ~12 MGD Scrubber

Blowdown• ~5 MGD Effluent• ~1 MGD Leachate

Conceptual Diagram of Stream Characterization Phases

Ammonia-N Total P

Wastestream mg /L mg /L

Digester Gas Scrubber 1 10.8 2.9

Digester Gas Scrubber 2 18.9 3.1

Centrate 868.5 60.35

Secondary Effluent 20.6 1.65

Landfill Leachate 44.3 0.44

Nutrient Reduction -Nitrogen averaged annual 6.3 million lbs

FRP Injection Tubing Installation

Fiberglass Reinforced Plastic (FRP) injection tubing is installed with threaded connections and properly

torqued by a Make-up Service Company

Temporary Steel Casing Installation

Fe

et

be

low

la

nd

su

rfa

ce

(b

ls)

10000’

Boulder Zone

Sub-FloridanConfinement Zone

Potential Injection Zone

Base of USDW at 1,360’ bls

Corrosive Deep Saline Groundwater

• TDS could be 300,000 mg/L

• High H2S concentrations

• Potential permanent damage to drill pipe from long term exposure.

• Potential damage to geophysical logging equipment.

• Potential surficial aquifer contamination from spillage of super saline brine on ground.