Algae Event June 1, 2012 Lorne Park Water Treatment Plant - PowerPoint PPT Presentation

Algae Event June 1, 2012 Lorne Park Water Treatment Plant

Overview  The Storm and the Algae  The Equipment Damage  The Recovery  The Repairs  The Impact on the Membranes

Water Treatment Capacity  Lakeview WTP  1150 ML/d (800 ML/d membranes)  Lorne Park WTP  500 ML/d (380 ML/d membranes)

Lorne Park Treatment Processes Conventional / UV Plant (120 ML/d) Sodium Hypochlorite Coagulant Low Lift Pumping Station Intake Coagulation Sedimentatio n Flocculation GAC Filters UV High Lift PS Zone 1 New Low Lift Pumps and Fine Screens UV Zone 2 Reservoir Membrane New Membrane Filtration GAC contactors Equalization Tanks (retrofitted Sedimentation (retrofitted filters) (ex. flocculation tanks) Tanks) Membrane/ UVAOP/ GAC Plant (380 ML/d)

Membranes  380 ML/d capacity  16 trains  7800 individual modules  Warranty based on: influent 1mm screening, coagulant type (among other conditions)

The Storm Raw Water Turbidity Trend  June 1 st , 2012  Rain: 37.4 mm 30 ntu  Wind: 59 km/h (East)  Turbidity 1 to 60 NTU is common  during storms  Long-stringy Algae

Standard Methods: Filter-clogging algae

Algae Coating

Travelling Screen Damage  1 mm travelling screens  Large differential caused damage of baskets  Screens couldn’t rotate  algae passed around bent screens

Low Lift Pump Basket Damage  Basket coated in algae  Pump taken out of service  11 p.m. to fully understand extent of damage

The Solution  Several attempts to get 1 mm screened water to membranes  Conventional and membrane plants are hydraulically separated by 1.5 m

Lorne Park Treatment Processes Conventional / UV Plant (120 ML/d) Sodium Hypochlorite Coagulant Low Lift Pumping Station Intake Coagulation Sedimentatio n Flocculation GAC Filters UV High Lift PS X Zone 1 New Low Lift Pumps and Fine Screens UV Zone 2 Reservoir Membrane New Membrane Filtration GAC contactors Equalization Tanks (retrofitted Sedimentation (retrofitted filters) (ex. flocculation tanks) Tanks) Membrane/ UVAOP/ GAC Plant (380 ML/d)

Fixing the Flow Rate  Interconnect valve approx. 30% open  Reprogram SCADA  60 ML/d using 4 Membrane Trains  Switch from 1 mm to 10 mm screens June 1

The Repairs  Repair crew consolidated undamaged baskets into one screen  7 days for one screen  8 weeks to repair second screen  27 damaged baskets in total

The Membranes  3240 modules exposed to the unscreened algae for several hours  2160 modules exposed to 10 mm screened water with coagulant for 7 days

Impact on the Membranes Algae Chlorine Citric Event Clean Clean

Acknowledgements  Ontario Clean Water Agency  Consultants  AECOM, GENIVAR  Contractors  Kenaidan, Maple Reinders  Equipment Suppliers  GE Water & Process Technologies (membranes)  Siemens (travelling screens)