Patti Fuller-Bloechl Muscatine WPCP

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1 DEIONIZED WATER SYSTEM Patti Fuller-Bloechl Muscatine WPCP

2 Overview City Source Water Testing Uses for the Deionized Water System BOD Preparation of Deionized Water Water System Components and Cost of Use Issues we have experienced Positive and Negative Aspects of the System

3 Muscatine WPCP Source Water City of Muscatine water is supplied from a 50 square mile aquifer which consists of sand and clay Supplied by Muscatine Power and Water City Owned Does not require much pretreatment Chlorine, Fluoride Issues - Hard Water WPCP sits at the bottom of the bluff from where the water is stored and brings in a lot of black sediment from Magnesium and sand The Pressure of water coming into the plant is PSI

4 Metals in Source Water Testing performed by Muscatine WPCP EPA Arsenic Barium Calcium Copper Iron Mercury Potassium Magnesium Manganese Sodium Lead City Water Report Limit MDL Result mg/l ug/l ug/l < < <

5 Muscatine Lab Water Uses E. coli sterilized water Required to have low bacteria water to make Sterilized Water for E. coli testing Cost of purchasing sterilized water was about $8 per 100 ml Cost for making sterilized water = Toxicity testing of our washing procedures 1 time fee of ~$100-$200 Monthly Heterotrophic Plate Count - $14/sample plus shipping Cost for sending out sample - $288 per year vs purchase of Sterile Water $350 (testing samples per year) RO type III water is fed into the flask washer/lab dish washer

6 Lab Water Uses (con t) Metals Testing Metal Finishing/ Categorical Industrial Dischargers in Muscatine is 14 (8 of which are metal finishers) Muscatine WPCP performs testing using a Dual ICP on industries, WPCP Influent and Effluent (and Primary Effluent), monitor lift stations, storm water run off, and dry weather stream testing BOD/CBOD Testing Use 2 day old cured water for testing, Type I Test BOD samples per week Test Industrial, WPCP and some outside work

7 BOD Analysis BOD analysis is performed by YSI LDO using the YSI Software Water Used Type I Pure Water Volume of Water 19 L carboy and a 9 L Carboy 3 days per week Water Procedure Water is typically drawn 2 days ahead Sits in dark for one day 19 L Aerated with a fish tank aerator for 2 hours in BOD Incubator and sits overnight phed between 6.5 and 7.5 HACH buffer added on day of use

8 Water System Lab water is run through a water softener before going g into the lab The water is filtered through a 5 micron, carbon wrapped whole house filter from Menards System Cost Purchased in 2008 for $9,000 (not including storage system) Water feeds into a (Formerly) Barnstead Diamond Reverse Osmosis

9 Water System Wall Mounted 100 L Storage Tank RO System (below) Whole House Pre-Filter Deionized Water System

10 Whole House Filter Changed every 2-4 weeks MPW flushing the lines the pre-filter is changed weekly During droughts filter is changed every 1-2 weeks Normal amount of water changed once per month

11 RO Water System The RO Water System Produces Type III water for the laboratory (as defined by the manufacturer) Requires < 3ppm Free Chlorine, Iron <0.5 ppm, Silica <30 ppm System produces 12 Liters/Hour Replaced an existing system, which was used for BOD analysis (Manufacturer did not recommend for BOD analysis) Filter Schedule Replace Carbon Filter Monthly (or when signaled 1-2 months) Replace RO Membrane Yearly Signal as to when to replace Feeds into a 100 L storage tank mounted on the wall Supplies Water to the Dish Washer and the Deionized Water System

12 Deionized System Deionized System (Formerly) Barnstead Diamond Nano Pure UV Features Carbon Rapped to remove residual chlorine 0.2 micron filter for final water polish (micro-organisms are > 0.2 micron) UV Disinfection of Microorganisms Calibrate internal Conductivity Meter Yearly electronically Produces pure water 18.2 micro Ohms UV Light sanitizes at two wavelengths 254 and 185 nm 185 nm produces hydroxyl free radicals to oxidize residual organic carbon and CO2

13 Deionized Ultrapure System System produces good water to use for ICP and Ion Chromatography Filters to 0.2 um Easy to install Cartridge Pack Replace the Cartridge Pack every 3-4 months and sanitize the system Automatic Cleaning Cycle

14 Annual Costs to Run 2014 Cost per Item Number Total Pre Filtration Reverse Osmosis Deionized Filter System Whole House Filter 7 15 $ 105 Rock Salt RO Carbon Filter $ 900 RO Treatment Filter 80 4 $ 320 RO Membrane $ 500 UV Bulbs $ 480 Deionized Filter Pack $ 2,600 Cleaning Agent 35 4 $ 140 Total $ 5,045

15 Metals in Deionized Water Testing performed by Iowa State Hygienic Laboratory Arsenic Barium Calcium Copper Iron Mercury Potassium Magnesium Manganese Sodium Lead City Water Report Limit Method Result mg/l ug/l EPA < < < < < < < < < < <

16 ISSUE: Constantly Changing gfilters on RO System for Carbon Carbon Filters were going g bad more quickly due to the source water Initially had a 10 micron filter (not carbon wrapped) Carbon Wrapped Filter Knocks down Chlorine in system which can cause issues with the filters, Changing g the Prefilter prevents the RO Membrane and Carbon Membranes from becoming clogged

17 Issues with Elevated BOD Blanks Blanks are usually mg/l BOD blanks are closer to the 0.2 mg/l limit Cause for high blanks for BOD is most likely nitrogen related Occasionally we get a hit with Ammonia with our system Fix to problem Very Dilute Bleach Set over night (200 ml) Rinse 100 L four or five times before using again Needs to be done every 6 months

18 BOD Blanks decreasing in depletion Blanks go from a positive number to a negative number Potentially caused from Algae growing in the 100 L tank Problem Fix Clean out the 100 L tank with Enzyme Cleaning solution ERA Free Enzyme Detergent Kill sources of Algae Rinse Line from 100 L tank to Deionized Filter System Place a hose wrap around the feed from the tank to the system to inhibit Algae growth

19 All Dilution Water Bad Blanks are mg/l (data is thrown out) Most likely cause is due to Sanitation Process of Deionized Water System Resolved by : Corrective Action Rinse Deionized System with 50 liters of water after sanitation before using the water again

20 Uncontrolled/Unregulated Incoming Water Pressure Due to the size of the service line into the plant, variable water pressure coming into the plant Problems it cause Back Pressure issues on the pump system greater than pressure pump is to pressurize to on the RO Unit Fix Add a pressure relief valve Replace DI Water system pump p when it wears out

21 Conclusion Water system delivers pure water May consider purchasing a Type II RO System It is easy to use from the previous system that we had System is not noisy or loud Monthly maintenance is required Relatively low cost to purchase, but more expensive to run on a yearly basis Replacement Pumps were a little difficult to obtain, but was able to get field sales rep to release pump for emergency