Water Resources Langelier Index Summary for Public Water Supplies in Management Division Newfoundland and Labrador Community Name Serviced Area Source Name Sample Date Langelier Index Bauline Bauline #1 Brook Path Well May 29, 2020 -1.06 Bay St. George South Highlands #3 Brian Pumphrey Well May 20, 2020 -0.29 Highlands Birchy Bay Birchy Bay Jumper's Pond May 06, 2020 -2.64 Bonavista Bonavista Long Pond May 01, 2020 -1.77 Brent's Cove Brent's Cove Paddy's Pond May 19, 2020 -5.85 Centreville-Wareham-Trinity Trinity Southwest Feeder Pond May 21, 2020 -3.64 Chance Cove Upper Cove Hollett's Well Jun 11, 2020 -2.17 Channel-Port aux Basques Channel-Port Aux Basques Gull Pond & Wilcox Pond May 20, 2020 -2.41 Clarenville Clarenville, Shoal Harbour Shoal Harbour River Jun 05, 2020 -2.23 Conception Bay South Conception Bay South Bay Bulls Big Pond May 28, 2020 -1.87 Corner Brook Corner Brook (+Massey Trout Pond, Third Pond (2 Jun 19, 2020 -1.88 Drive, +Mount Moriah) intakes) Fleur de Lys Fleur De Lys First Pond, Narrow Pond May 19, 2020 -3.41 Fogo Island Fogo Freeman's Pond Jun 09, 2020 -6.65 Fogo Island Fogo Freeman's Pond Jun 09, 2020 -6.54 Fogo Island Fogo Freeman's Pond Jun 09, 2020 -6.33 Gander Gander Gander Lake May 25, 2020 -2.93 Gander Bay South Gander Bay South - PWDU Barry's Brook May 20, 2020 -4.98 Gander Bay South George's Point, Harris Point Barry's Brook May 20, 2020 -3.25 Grand Falls-Windsor Grand Falls-Windsor Northern Arm Lake Jun 01, 2020 -2.80 (+Bishop's Falls, +Wooddale, +Botwood, +Peterview) Grates Cove Grates Cove Centre #1C Well Jun 09, 2020 -0.35 Happy Valley-Goose Bay Happy Valley-Goose Bay Spring Gulch May 08, 2020 -3.17 Happy Valley-Goose Bay Happy Valley-Goose Bay Well Field (connect summer May 08, 2020 -3.31 2002) Harbour Grace Harbour Grace South Lower New Southside Well Jun 17, 2020 -0.29 (Well#3) Harbour Grace Harbour Grace South Upper Southside Wellfield (Well Jun 17, 2020 -0.04 #1 & #2) Harbour Grace Thickett #2 Thicket New Well Jun 17, 2020 -0.32 Labrador City Labrador City Beverly Lake May 12, 2020 -1.48 Lewisporte Lewisporte Stanhope Pond May 06, 2020 -4.00 Lewisporte Lewisporte Stanhope Pond Jun 08, 2020 -4.21 Marystown Marystown Fox Hill Reservoir / Clam May 17, 2020 -3.84 Pond Mount Pearl Mount Pearl Bay Bulls Big Pond May 28, 2020 -1.89 New Harbour New Harbour Williams Hill Well May 26, 2020 -0.04 Norris Arm Norris Arm (south) Mill Lake May 06, 2020 -4.42 Paradise Paradise Bay Bulls Big Pond May 28, 2020 -1.89 Point of Bay Point of Bay Indian Cove Pond Jun 03, 2020 -3.22 Port au Choix Port au Choix Well Field Jun 10, 2020 -0.33 November 18, 2020 Page 1 of 3 Water Resources Langelier Index Summary for Public Water Supplies in Management Division Newfoundland and Labrador Community Name Serviced Area Source Name Sample Date Langelier Index Port au Port Port au Port West, #1 & #3 & #6 FatherJoy's May 07, 2020 0.03 West-Aguathuna-Felix Cove Aguathuna Well Portugal Cove-St. Phillips Portugal Cove-St. Phillips Bay Bulls Big Pond May 28, 2020 -1.85 Pouch Cove Pouch Cove North Three Island Pond Jun 03, 2020 -3.85 Ramea Ramea Northwest Pond May 24, 2020 -2.36 Ramea Ramea - PWDU Northwest Pond May 24, 2020 -4.31 Reidville Reidville Humber Canal, Grand Lake Jun 18, 2020 -3.41 Small Point-Adam's Blackhead #4 Well - Leonard King Well Jun 23, 2020 -0.18 Cove-Blackhead-Broad Cove Small Point-Adam's Blackhead #4 Well - Leonard King Well Jun 23, 2020 -0.45 Cove-Blackhead-Broad Cove St. Anthony St. Anthony St. Anthony Pond Jun 16, 2020 -3.31 St. John's St. John's Windsor Lake May 13, 2020 -2.24 St. John's St. John's Windsor Lake Jun 19, 2020 -2.08 St. John's St. John's Petty Harbour Long Pond May 13, 2020 -1.50 St. John's St. John's (+Mt. Pearl, Bay Bulls Big Pond May 28, 2020 -1.70 +Paradise, +Portugal Cove-St. Phillips, +CBS) St. Pauls St. Pauls Two Mile Pond Jun 17, 2020 -1.37 Steady Brook Steady Brook Wellfield + Steady Brook Jun 19, 2020 -2.01 Stephenville Stephenville Well Field May 07, 2020 0.02 Terrenceville Terrenceville Big Brook Jun 09, 2020 -5.38 Wabana Wabana #3 Yard West Mines Road Jun 15, 2020 -0.02 Wabana Wabana Mixed Supplies Jun 15, 2020 0.09 Wabana Wabana Mixed Supplies Jun 15, 2020 -0.07 Wabana Wabana Mixed Supplies Jun 15, 2020 0.00 Wabana Wabana - PWDU #3 Yard West Mines Road Jun 15, 2020 -5.10 November 18, 2020 Page 2 of 3 Water Resources Langelier Index Summary for Public Water Supplies in Management Division Newfoundland and Labrador Community Name Serviced Area Source Name Sample Date Langelier Index What is the Langelier Index? The Langelier index (LI) is an approximate measure of the degree of saturation of calcium carbonate in water. It is calculated using the pH, alkalinity, hardness, total dissolved solids, and water temperature of a water sample collected at the tap. If the; · LI is negative: The water is under saturated with calcium carbonate and will tend to be corrosive in the distribution system · LI is positive: The water is over saturated with calcium carbonate and will tend to deposit calcium carbonate forming scales in the distribution system · If LI is close to zero: The water is just saturated with calcium carbonate and will neither be strongly corrosive or scale forming. The LI is one of several tools used by the water operator for stabilizing water to control both internal corrosion and the deposition of scale. Experience has shown that LI in the range of -1 to +1 has a relatively low corrosion impact on metallic components of the distribution system. LI values outside this range may result in laundry stains or leaks. For additional information on the Langelier Index please contact the Department of Municipal Affairs and Environment at 729-2563. November 18, 2020 Page 3 of 3.