Recycled Water: A New Source for Private Water Systems in Ohio

Transcription

1 Recycled Water: A New Source for Private Water Systems in Ohio 2017 OHIO SECTION ANNUAL CONFERENCE September 27, 2017 Michelle J. Matty, Adam J. Arnold and Philip J. Schmidt

2 TRADITIONAL WATER MANAGEMENT 2

3 TRADITIONAL WATER MANAGEMENT 3

4 DIRECT POTABLE REUSE (DPR) 4

5 ONSITE DIRECT POTABLE REUSE (DPR) 1. Wastewater Treatment 2. Advanced Purification 3. Purified Water Storage/Delivery 5

6 MOTIVATION FOR ON-SITE DPR In Ohio, 700,000 homes, and many businesses, rely on private water systems Centralized infrastructure not available/too costly Most common private water system Well for water supply Septic system for sewage discharge Paradigm is complicated by: Limited water availability Degraded water quality Challenges in sewage discharge 6

7 MOTIVATION FOR ON-SITE DPR 7

8 MOTIVATION FOR ON-SITE DPR 8

9 MOTIVATION FOR ON-SITE DPR 9

10 MOTIVATION FOR ON-SITE DPR 10

11 MOTIVATION FOR ON-SITE DPR Arsenic 11

12 MOTIVATION FOR ON-SITE DPR 12

13 MOTIVATION FOR ON-SITE DPR 13

14 MOTIVATION FOR ON-SITE DPR 14

15 MOTIVATION FOR ON-SITE DPR 15

16 MOTIVATION FOR ON-SITE DPR 16

17 MOTIVATION FOR ON-SITE DPR In the U.S. ~ 25% of rural and suburban homes, and many businesses, rely on private water systems Centralized infrastructure not available/too costly Most common private water system Well for water supply Septic system for sewage discharge Paradigm is complicated by: Limited water availability reduce water withdrawals Degraded water quality provide safe and consistent Challenges in sewage discharge water supply reduce waste and nutrient loading 17

18 TAKING ACTION IN OHIO 18

19 TAKING ACTION IN OHIO 19

20 TAKING ACTION IN OHIO 20

21 TAKING ACTION IN OHIO Three modular components Preliminary Purification ~ Wastewater Treatment Advanced Purification ~ Full Advanced Treatment Purified Water Storage/Delivery ~ ESB/Distribution Multi-barrier design philosophy Biological treatment, membrane filtration, RO, UV advanced oxidation/disinfection, chlorination Automated system control Over 30 sensors with continuously logged data Immediate recirculation/shut-down in event of anomalous data Operator notification when service needed 21

22 TAKING ACTION IN OHIO WRLC Office Complex Salt Softening, UV Disinfection Well Water Storage Reservoir Well Trash Trap Preliminary Purification Advanced Purification Purified Water Storage & Delivery Experimental Concurrence OAC (B) Dose Tank Phase I flowpath Concentrated salt disposal April 2013 through July 2014 Drip/Leach Field 22

23 TAKING ACTION IN OHIO Purified water met existing drinking water standards Challenge testing demonstrated treatment system performance and capabilities Pathogen reduction exceeded even the most stringent requirements Sensitivity of process control verified through intentional failure of key process units 23

24 TAKING ACTION IN OHIO Occasional NDMA, NDEA detections over 10 ng/l and chlorate detections over 210 µg/l at startup; eliminated towards end of Phase I DBP formation control Removal of anion exchange resins Supplemented alkalinity and carbon within biological treatment processes Reduction of free chlorine residual from 1.0 mg/l to 0.4 mg/l Switch from sodium to calcium hypochlorite 24

25 TAKING ACTION IN OHIO WRLC Office Complex Salt Softening, UV Disinfection Well Water Storage Reservoir Well Preliminary Purification Advanced Purification Purified Water Storage & Delivery Well Supply to WRLC is shutoff except during a Watercycle water quality emergency or supply shortage. It is periodically used to top-up the Watercycle at the lift station, which also helps to refresh the well water storage reservoir. Director s Variance OAC (A) Trash Trap Dose Tank Phase II Watercycle flowpath Concentrated salt disposal Top-Up Supply s August 2014 through November 2015 (limits on drinking/cooking) Drip/Leach Field 25

26 TAKING ACTION IN OHIO WRLC Office Complex Salt Softening, UV Disinfection Well Water Storage Reservoir Well Preliminary Purification Advanced Purification Purified Water Storage & Delivery Well Supply to WRLC is shutoff except during a Watercycle water quality emergency or supply shortage. It is periodically used to top-up the Watercycle at the lift station, which also helps to refresh the well water storage reservoir. Director s Variance OAC (A) Trash Trap Dose Tank Phase II Watercycle flowpath Concentrated salt disposal Top-Up Supply s December 2015 through May 2016 (unrestricted use) Drip/Leach Field 26

27 TAKING ACTION IN OHIO Demonstration system continues to supply purified water for unrestricted use > 500,000 gallons of water re-used, to date Purified water analysis for E. coli, nitrate and DBPs Regulatory review of all process-related changes 2015/16 Private Water System (PWS) Rule Review Included placeholders for recycled water rules Strategy for development of recycled water rules Continue to engage expert technical panel Develop draft recycled water rules Key stakeholder review and comment 27

28 SUMMARY Where conventional private water system alternatives are unavailable or problematic, on-site DPR systems can: reduce withdrawals of water resources from the environment provide a safe and consistent supply of water reduce waste and nutrient loading to the environment Pilot project at WRLC headquarters successfully demonstrated the above As of 2014 there exists a legislative mandate in Ohio to promulgate recycled water as an approved water source for private water systems 28

29 IS ON-SITE DPR A VIABLE NEW SOURCE OF WATER FOR OHIO? This modern option for private water systems will make a positive impact on our future water reserves. As in so many cases related to sustainable practices, the risk of doing nothing is far greater than the risk associated with embracing new approaches. - Senator John Eklund On-site DPR is an emerging option for sustainability in Ohio providing a new safe and environmentally friendly source of private water. 29

30 ACKNOWLEDGEMENTS 30

31 Michelle J. Matty (440)