Desalination for Drinking Water Purposes TCEQ Trade Fair David A. Williams, P.E Robert W. Sims, P.E. Austin, Texas May, 2016

Why New Desal Rules? RO Technology has existed for decades Manufacturer’s modeling tools have proven to be reliable Allows a shorter path for approval of desalination plants

Two Steps for Desal For System’s Proposing RO or NF Membranes: 1. Models and supporting info with Engineering Report (§290.39(e)(6)) 2. Baseline Data at Start-Up (§290.39(e)(7))

Step 1 – Models + 1. Manufacturer’s RO/NF Model w/ the Engineering Report a) Flow rate b) Recovery c) Number of Stages d) Number of Passes e) # vessels per stage, # elements per vessel f) Feed pressure g) Flux h) Ion concentrations of the feed water

Step 1 – Models + 2. Well Construction Records 3. Pretreatment Description a) Constituents removed b) Technology used c) Operating Parameters 4. NSF 60 and 61 Certification 5. Post-Treatment/Blending

Step 1 – Models + 6. DBP formation potential 7. Membrane Integrity/Cleaning a) Increased Salt Passage b) Change in pressure differential c) Change in normalized permeate flow

Step 2 –Baseline Data Step 2 required before the RO or NF system can be used to produce drinking water

Step 2- Baseline Data Baseline Data at Start-Up includes: Net Driving Pressure Normalized Permeate Flow Salt Rejection or Salt Passage

Step 2 - Baseline Data Using Baseline Data, the engineer shall: Set Trigger for Clean In Place (or define set time interval) Check Model’s Accuracy Verify Plant Capacity

Step 2 (continued) In addition to Baseline Data, provide: Complete Chemical and Physical Analysis of Water (in accordance with §290.42(c)(3)(G) for raw water, permeate water, and post- treatment water

Design Rules of RO/NF §290.42(b)(9) Based on Engineering Report Design basis: Computer models Pilot study Alternate site data Manufacturer’s allowable operating parameters for units rated less than 300 gpm

Design Rules of RO/NF §290.42(b)(9) Must provide adequate cleaning Must provide acceptable pretreatment techniques: Must be ANSI/NSF 60 or 61 Bags, cartridges, or screens for particulate Chemicals for scale, foulants, chlorine removal Filters for iron and manganese Degasification (aeration) Ion-exchange softening

Design Rules of RO/NF §290.42(b)(9) Post-Treatment must be provided for: Corrosivity control (remineralization) Removal of dissolved gases (carbon dioxide, hydrogen sulfide) Matching water quality goals Must be ANSI/NSF 60 or 61

Other General Design Requirements §290.42(b)(9) Pipes and pipe galleries compliant with §290.42(d)(12) and (13) Equipped to monitor conductivity or TDS Chemical Storage Compliant with §290.42(f) Cross connection protection Flow metering devices (feed, permeate, and concentrate) Pressure monitoring (before and after stages) Temperature monitoring (± 0.5º C)

Other RO/NF Rules §290.42(d)(17) - New rules can be used for surface water systems (but not for microbiological control) §290.45(a)(6) – RO/NF capacity must be sized in consideration of losses and wastes §290.46(e)(2)(D) – RO/NF Operators must have at least one TCEQ approved course or event §290.46(f)(3)(A)(iv) – Maintain records of each CIP event §290.46(f)(3)(B)(x) – Maintain records of conductivity (or TDS), pressure, temperature, and flow §290.46(s)(2)(G) and (H) – Calibration requirements for conductivity, pressure, and temperature instruments

Brief Summary of Other Rule Changes, effective July 2015 Chloramination, §290.42(e)(3)(G) Definition of “Significant Change” §290.39(j) Enforceability of Exceptions, §290.39(l)(4) and (5) Well Construction Review, §290.41(c)(3)(C) Alternative Overflow Devices, §290.43(c)(3) Water Storage, §290.43(c) Water Distribution Crossings, §290.44(e)(4)(B) Lead Content, §§290.41(c)(3)(B), (b)(1), (i),& Figure (b) LT2 Changes, § (b)(3)(B)(i) & (ii)

New and Updated Checklists

Forms and Checklists for Public Water System Operators Submitting Plans or Specifications Forms and Instructions Public Water System Plan Review Submittal Form (TCEQ-10233) Sanitary Control Easement Form (TCEQ-20698) Core Data FormCore Data Form (for new systems) (TCEQ-10400) Financial Ability Form Checklists Chloramine Checklist Membrane Construction Checklist - Step 1 Membrane Use Checklist - Step 2 Water Distribution Construction Checklist Pressure Tank Construction Checklist Checklist for a Proposed Public Water Supply Well/Spring Public Well Completion Data Checklist For Interim Approval Water Storage Tank Construction Checklist

Questions? David A. Williams, P.E. Technical Review & Oversight Team (512) Robert W. Sims, P.E. Plan Review Team (512)