Water Quality Reports - Decew

The Decew Falls Water Treatment Plant provides water to St. Catharines and portion of Thorold, Lincoln and Niagara-on-the-Lake.

Current Status

The values below represent the water quality leaving the water treatment plant on the date indicated with the exception of pH which is for distribution water.

These values are updated on a monthly basis and measured by a laboratory that is certified by the Ministry of Environment, Conservation and Parks.

ParameterValueSample DateRangeTarget in Range
Alkalinity93 mg/LMay 4, 202630 - 500 mg/LTarget in range Safe and within our expected range
Hardness131 mg/LMay 4, 2026100 - 150 mg/LTarget in range Safe and within our expected range
pH7.65 June 1, 20266.5-8.5Target in range Safe and within our expected range
E. ColiNot detectedMay 25, 20260 counts/100 mLTarget in range Safe and within our expected range
Total ColiformsNot detectedMay 25, 20260 counts/100 mLTarget in range Safe and within our expected range
LeadNot detectedMay 4, 20260-0.01 mg/LTarget in range Safe and within our expected range
Chloride27.5 mg/LMay 4, 20260 - 250 mg/LTarget in range Safe and within our expected range
Sodium14.9 mg/LMay 4, 20260-20 mg/LTarget in range Safe and within our expected range
Sulphate42.9 mg/LMay 4, 20260 - 500 mg/LTarget in range Safe and within our expected range
Fluoride0.07 mg/LMay 4, 20260 - 1.5 mg/LTarget in range Safe and within our expected range
Vinyl ChlorideNot detectedMay 4, 20260-0.001 mg/LTarget in range Safe and within our expected range
Calcium38.5 mg/LMay 4, 2026 No current standards or guidelines for this parameter
Magnesium8.53 mg/LMay 4, 2026 No current standards or guidelines for this parameter

For more information about the quality of water in your local distribution system, contact your area municipality.

Reports

Under Ontario Regulation 170/03, Niagara Region and the area municipalities are responsible for providing water quality reports.

2025

2024

2023

2022

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