CITY OF MINNEAPOLIS Fridley Filter Plant Rehabilitation MINNEAPOLIS WATER WORKS Public Works Department Water Treatment & Distribution Services Division
Overview Minneapolis Water Fridley Filter Plant History Project Benefits Construction to Date Next Phase 2
Minneapolis Water Source water Mississippi River Max capacity 140 MGD Average rate 57 MGD 2017 total production 19.5 billion gallons 24/7 365
Distribution Area 1,000 miles of water mains bring water to 400,000+ customers in the Minneapolis Metro area, including: New Hope Crystal Golden Valley Columbia Heights Hilltop Morningside Edina MSP airport Bloomington (partial) New Brighton (temporary)
MISSISSIPPI RIVER Treatment System Overview KMnO 4 (optional) Alum Lime PAC PAC (2 points) Carbon Dioxide MIX FRIDLEY CAMPUS SOFTENING RECARBONATION TO RESIDUALS Chlorine Ammonia Ortho/poly phosphate Fluoride Sodium Hydroxide Ferric Chloride Chlorine Ammonia Polymer MIX COAG / SETTLE FILTERS RESERVOIRS DISTRIBUTION RESERVOIR MIX COAG / SETTLE FILTERS DISTRIBUTION COLUMBIA HEIGHTS CAMPUS RESERVOIRS ULTRAFILTRATION
Fridley Campus 6
Fridley Filter Plant Constructed in 1920 s
Filter Building ~ 440 feet long 20 filters
9
Needs for the Historic Plant Age of valves Filter washing and operations to modern standards Rate control Air scour/new underdrains Filter to waste Taste and odor control opportunity Backwash system upgrade Recycle spent filter backwash water 11
Pre Project Work FFP Split 3.5 million dollar project Maintain level of service during rehab construction Split the existing plant to allow for half of the filters to stay in service during construction 12
FFP Spilt Completed in 2014 13
Rehab Project at a glance Reconstruct filters Use original filter box Opportunity to abate asbestos and lead paint Add Granular Activated Carbon media Add air scour to clean filters Remove and replace pipes in gallery Contact Tanks (Disinfection) Backwash supply tank Backwash water recovery system
Coop Mixing Chambers Office West Filters East Filters Backwash Recovery Tank West Contact Tank Blower East Contact Tank Fridley Filter Plant Rehabilitation Backwash Supply Tank
Blower Backwash Recovery West Contact Basin East Contact Basin BW Supply Tank
FFP Rehab: It Begins 17
FFP Rehabilitation Construction begins July 2016. Five year project Backwash water tower built first East filters taken out of service January 2017 Where are we today? 18
Winter 2018 Construction Status 19
FFP Rehabilitation 20
Backwash Supply Tank 21
Backwash Supply Tank 22
Backwash Water Tank 500,000 gallons 16 inch feed from existing campus water 36 inch backwash line Allow backwashing of all 20 filters in 48 hours 23
East Contact Tank 24
Contact Tank 25
Contact Tank 26
Contact Tank 350,000 gallons each 27
Contact Tanks 28
Contact Tanks Needed to make up for lost CT due to post filtration disinfection Approx. 350,000 gallons each Baffled to maximize contact time Multiple options for chlorine and ammonia injection Sodium hydroxide added post final disinfectant addition 29
Backwash Recovery Tank 30
Backwash Recovery Tank 31
Backwash Recovery Tank 32
Backwash Recovery Tank 33
Backwash Recovery Tank 34
Backwash Recovery Tank 35
Backwash Recovery Tank 500,000 gallons Spilt in half 4 variable speed pumps recycle spent BW water to head of softening plant Replaces a pipeline/pump system and will allow for more frequent backwashing and better control of flow into softening plant 36
Filters 37
Filters 38
Filters 39
Filter Underdrain - 1968 40
Filters 41
Filters 42
Filters 43
Filters 44
FFP Rehab Project: New underdrains Image courtesy of AWI 45
Filters Pipe Gallery 46
Filters Pipe Gallery 47
Filters 48
Filters 20 Filters Area = 1400 sq ft 20 inches GAC/12 inches sand Air scour Filter to waste EBCT from 3-17 minutes 49
Filters GAC over anthracite decision made early on in project Passive T&O control system Spend $1,000,000 on PAC St. Paul s experience with GAC switch Biologically active but run as conventional filters Extensive and ongoing piloting GAC performance T&O and CEC removal 50
University of Minnesota Research CEC s removal via pilot plant Blood pressure med, herbicide, anticonvulsant, antidepressant, lipid regulator, antibiotic, flame retardant Atenolol, Atrazine, Carbamazepine, Fluoxetine, Gembfibrozil, Metolachlor, Sulfamathoxazole, TCEP Removal mechanisms were adsorption and biodegradation 51
Ongoing research Arcadis Water Research Foundation Project 4669 NDMA, Perfluorinated compounds, algal toxins 52
FFP Rehab What s left? Finish backwash recovery tank Build west contact tank Connect BW tank and BWR tank East filters online in early 2019 West filters online in late 2020 53
Thanks to: Dale Folen, Project Engineer MWW CDM Smith U of M 54
Questions? 55