Alternative Water Supplies: Wastewater Reuse by Groundwater Recharge

1
Alternative Water SuppliesWastewater Reuse by
Groundwater Recharge
2
Population Growth
Year Residents (millions) Water Use (billion gallons per day)
1995 15.9 7.2
2020 21.8 9.1
Source Department of Environmental Protection Source Department of Environmental Protection Source Department of Environmental Protection
High Demand Less Resource
Less Resource Resource Control
3
Regional water rule turns off tap to the
Biscayne Aquifer in SE Florida

• Regional System Water Availability Rule (2007)
• Locked in current levels
• No additional Biscayne use
• Alternative Water Supply

4
Alternative Water Supplies

• Floridan Aquifer
• Aquifer Storage Recovery
• Demand Management
• Wastewater Reuse
• Irrigation (Purple Pipe)
• Surface Water Recharge
• Groundwater Recharge

5
Purple PipeLimited Application in SE Florida

• Treatment
• Simple
• Cost-Effective
• Construction in built out areas
• Expensive
• Disruptive
• Opportunistic use

6
Surface Discharge Costly Treatment / Credit
Uncertain

• Wetlands
• Canals
• Nutrient removal
• Regulatory issues
• Impaired waters
• TMDLs
• Costly treatment
• Low Permit Credit

7
City of SunrisePilot Study Advanced WW Treatment
for Groundwater Recharge
8
Pilot Study Objectives

• Treat Raw Wastewater
• Florida Standards
• Broward Co. Standards
• Groundwater Recharge
• Nutrient (P) Removal to Low Levels
• Full Scale Application at Sunrise Southwest
  Facilities

9
Water Quality Standards
Compound Broward County Std Florida State Standard Water Quality Standard
CBOD5 5 mg/l 20 mg/l 5 mg/l
Total Suspended Solids (TSS) - 5 mg/l 5 mg/l
Chlorine (Total Residual) 1 mg/l - 1 mg/l
Total Nitrogen N.S. - 10 mg/l
Nitrate (as N) 10 mg/l 10 mg/l 10 mg/l
Nitrite (as N) 1 mg/l 1 mg/l 1 mg/l
Total Nitrate Nitrite 10 mg/l 10 mg/l 10 mg/l
Total Phosphates (as P) 0.01 mg/l - 0.01 mg/l
Fecal Coliform 200 / 100 ml - 200 / 100 ml
Total Coliform 1,000 / 100 ml - 1,000 / 100 ml
Total Dissolved Solids (TDS) 500 mg/l 500 mg/l 500 mg/l
Chlorides 250 mg/l 250 mg/l 250 mg/l
Turbidity 10 NTUs - 10 NTUs
10
Stirling Road
Pilot Plant SunriseSW WWTF
Southwest WTP
I-75

• Existing Plant
• Rated - 0.99 mgd
• Permit - 0.5 mgd
• Oxidation Ditches
• Percolation Ponds
• Destined to be decommissioned

Southwest WWTF
11
Proposed Upgrade to SW WWTF

• Proposal
• Upgrade to 2.0 mgd
• Convert Existing Facilities
• Add MBRs
• Recharge Aquifer

I-75
Pilot Plant Site
PercolationPonds
Oxidation Ditches
12
Wellfield Protection Zones
Production Wells
ZONE 1
ZONE 2
Regional Groundwater Flow
ZONE 3
1,100 ft
Flow Paths

• Zone 1 10 day
• Zone 2 30 day
• Zone 3 210 day

Rapid Infiltration Trenches
Groundwater Mounding
13
Infiltration Trenches
Perforated Overflow Collectors
Cap Rock Layer
Perforated Pipe

Geotextile Filter
Source USEPA, 1994
14
Pilot TreatmentStreams

• Control Stream
• MBR Only
• Stream A
• MBR RO
• Stream B
• MBR Chem P Removal

15
MBR Pilot Unit
16
Customized MBR Pilot Design based on BiowinTM
ANAEROBIC
ANOXIC
AEROBIC
POST-ANOXIC
MBR TANK
Alum
Acetate
Caustic
Influent
RAS
Permeate
WAS
17
Influent Wastewater Characterization
 Compound   Min Avg Max
CBOD5 mg/L 130 213 340
COD mg/L 420 479 620
TSS mg/L 62 118 230
Total Nitrogen mg/L 47 60 100
Total Phosphorus mg/L 8 22 33
Total Phosphate mg/L 6 8 11
Alkalinity mg/L 220 241 260
18
Suspended Solids Removal
19
Nitrogen Removal
20
Phosphate Removal
21
MicroconstituentRemoval/Oxidation Study

• Microconstituents emerging issue
• Wide variety present in wastewaters
• Pharmaceuticals (Analgesics, Antibiotics,
  Antidepressents, Contraceptives, Steroidal
  hormones, Lipid Control Drugs, etc)
• Stimulants (caffeine)
• Pesticides
• Impact on future treatment requirements

22
Critical Cost Factors

• Additional P Removal Required?
• RO Required?
• UV Dose
• Microconstituent Removal (future)

23
Public Health and Perception

• Keep public informed
• Engage community and industry leaders
• Address issues such as Microconstituents

24
Thank You
25
Thank You
26
Water Quality Goals

• State of Florida
• FAC 62-520.420 Class G-1 Drinking Water Stds
• FAC 62-610 Reclaimed Water/Land Application
• FAC 62-610.521 525 Setback Requirements
• FAC 62-650 Effluent Limitations
• Broward County Effluent Standards
• Municipal Codes Chapter 27 Section 196(b)
  regulates effluent discharge to groundwater

27
Thank You
28
Wastewater Characterization
29
ProjectSchedule

• Start-Up
• Set-Up
• Seeding
• Two Months
• Testing
• Four Months
• Total
• Six Months
• Completion
• Sep 2007

30
Floridan Aquifer will provide short-term relief

• Deep aquifer/ saline water
• RO treatment
• Sustainability issues

31
ASRs have not yieldedthe expected returns

• Regulatory issues
• Recovery issues ()
• Volume generated
• Well-drilling costs
• Convert to Floridan

32
Containerized MBR Pilot Unit
33
Selection of Micropollutants

• Likelihood of occurrence
• Major modes of action
• Chemical properties and effect on removal
  efficacy
• Analytical methods availability
• Cost of analysis

34
Target Micropollutants

• Analgesics ibuprofin, acetaminophen
• Antibiotics trimethoprin, acetaminophen
• Stimulants - caffeine
• Contraceptives - ethinylestradiol
• Antibacterials - triclosan
• Steroidal hormones progesterone, testosterone
• Pesticides atrazine, carbaryl, diazinon
• Antidepressents - fluoxetine
• Lipid Control Drugs gemfibrozil
• Viruses

35
Wastewater Characterization
 Compound   Test Result WQ Std
Total Dissolved Solids (TDS) mg/L 430 500
Chlorides mg/L 100 250
Aluminum mg/L 0.74 0.20
Iron mg/L 0.46 0.30
Zinc mg/L 140 5
Endosulfan µg/L 0.12 0.10