Virginia Walsh, PhD, P.G. Ed Rectenwald, P.G. February 25, 2016

Transcription

1 Miami-Dade Water & Sewer Department Nutrient Reduction by Use of Industrial Deep Injection Wells, Miami-Dade County, Florida Virginia Walsh, PhD, P.G. Ed Rectenwald, P.G. February 25, 2016 Miami-Dade Water and Sewer Department

2 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 ( km) 38,381 fire hydrants 126,913 valves

3 Wastewater System: WASD Overview 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

4 Ocean Outfalls WASD Water & Wastewater Treatment Facilities Deep injection wells

5 2008 Ocean Outfall Legislation Chapter , Laws of Florida Reduce nutrient loading to the ocean Meet Advance Wastewater Treatment (AWT) by Dec 31, 2018, or Reduce cumulative outfall loadings (from ) equivalent to AWT from December 31, 2025, stop using outfall and implement 60% reuse

6 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 ]). Requirement for High Level Disinfection (HLD) treatment facilities to be added at the South District Wastewater Treatment Plant (SDWWTP). An HLD facility is required before a permit for the construction of any new Class I municipal injection wells can be issued in South Florida, including Miami-Dade County.

7 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)

8 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

9 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

10 Preliminary seismic studies at Virginia Key in collaboration with USGS prior to drilling Seismic profiling at CDWWTP Miami-Dade County USGS Carbonate Aquifer Characterization Laboratory Davie, FL USGS PROVISIONAL DO NOT CITE

11 Central District Wastewater Treatment Plant Virginia Key

12 CDWWTP IW-1 Class V Injection Well Design 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 ,780 3,150 Base of USDW at 1,360 bls Boulder Zone Sub-Floridan Confinement Zone 7200 Permitted injection capacity is 19.9MGD ~1 MGD Centrate ~12 MGD Scrubber Blowdown ~5 MGD Effluent ~1 MGD Leachate ,000 Potential Injection Zone

13 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 HP DRAWWORKS

14 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

15 Large Diameter Boreholes Largest diameter borehole (46-inches) in Florida to a depth of 2,780 feet bls

16 Large diameter mudded borehole Cementing 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

17 Lithologic Descriptions, Core Analysis, Geophysical Logging, Packer Testing

18 Permeability within Cretaceous Aged Formation Complex 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.

19 Cretaceous Geology

20 Text Book Anhydrite Bulk Density = 2.96 gm/cc P e = 5

21 Cretaceous Permeable Units

22 24 inch: 26/30 $2.5 billion in HLD costs to comply with the Ocean Outfall Legislation 30 inch: 19/22 Determination of suitable sites for additional Class I Industrial Waste Wells Analysis to determine injection to Cretaceous formations cost effective vs traditional disposal zones

23 Questions? For further project or technical information contact: Virginia Walsh and Ed Rectenwald

24 CDWWTP Treatment/Disposal Method HLD Plant Boulder Zone Injection Wells Total for HLD w/boulder Zone injection wells NDWWTP* HLD Boulder Zone Injection Wells Total for HLD w/boulder Zone injection wells Total WASD System Wide CDWWTP/NDWWTP HLD and Wells $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

25 Presentation Outline Overview Objectives Preliminary Investigations Technical Design Construction Activities

26 Compliance with Ocean Outfall Legislation 59,874,077 lbs If build AWT for nutrient removal 2018: 60,015,437 lbs Centrate Deep injection well 2017: Reduce nutrient loading to the ocean Meet Advance Wastewater Treatment (AWT) by Dec 31, 2018, or Reduce cumulative outfall loadings (from ) equivalent to AWT from December 31, 2025, stop using outfall and implement 60% reuse

27 Documented Deep Geology Caverns in Miami-Dade County Well 6 Well 41 Central District WWTP Well 52 Miami-Dade CDWWTP Injection Well Rebecca Shoal Reef Possible permeable zones for injection

28 Geophysical Logging Dipole Shear Sonic Nuclear Magnetic Resonance Formation Microimager Neutron Porosity Optical Borehole Imaging Petroleum industry logs for analysis of mineral and porosity

29 Obtain discrete water quality data Validate log-derived results Estimate confinement properties Target monitor zones Packer Testing

30 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.

31 Formation Plugging and Precipitation Analysis Chemical Characteristics - Desktop Evaluation Preliminary Blended Waste Stream Evaluation Preliminary Blending of Combined Waste Stream with Groundwater Struvite NH 4 MgPO 4 6H 2 Blending Scenario 1 Blending Scenario 2 Parameters mg /L mg /L ph Ammonia-N Magnesium Total P Struvite Saturation Index Precipitation and Plugging Potential - Bench Scale Tests Blended waste streams Blended injectate with ambient aquifer water of injection zone

32 Conceptual Diagram of Stream Characterization Phases Blended Wastestream ~1 MGD Centrate ~12 MGD Scrubber Blowdown ~5 MGD Effluent ~1 MGD Leachate Ammonia-N Total P Wastestream mg /L mg /L Digester Gas Scrubber Digester Gas Scrubber Centrate Secondary Effluent Landfill Leachate Nutrient Reduction - Nitrogen averaged annual 6.3 million lbs

33 FRP Injection Tubing Installation Fiberglass Reinforced Plastic (FRP) injection tubing is installed with threaded connections and properly torqued by a Make-up Service Company

34 Temporary Steel Casing Installation Feet below land surface (bls) Base of USDW at 1,360 bls Boulder Zone Sub-Floridan Confinement Zone Potential Injection Zone

35 Corrosive Deep Saline Groundwater TDS could be 300,000 mg/l High H 2 S 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.