Decew Falls Water Treatment Plant - 2020 Annual Water Quality Report
The Annual Water Quality Report summarizes the quality of drinking water from the Decew Falls Water Treatment Plant from Jan. 1 to Dec. 31, 2020.
Description of Drinking Water System
A conventional surface water treatment plant incorporates the following steps in its purification process:
- Zebra mussel control
- Travelling screens
- Coagulation
- Flocculation
- Sedimentation
- Filtration
- Disinfection
The plant consists of three separate treatment trains; referred to as Plant 1, Plant 2, and Plant 3, with a combined rated capacity of 227,300 m³/day. Primary disinfection is achieved utilizing Sodium Hypochlorite with Ultraviolet light as enhancement.
The Decew Falls Water Treatment Plant supplies drinking water to the City of St. Catharines, City of Thorold, Town of Niagara-on-the-Lake, and sections of the Town of Lincoln, and is located at 2700 DeCew Rd.
The water treatment chemicals used over this reporting period are:
- Sodium Hypochlorite
- Aluminum Sulphate
Monetary Expenses Incurred
To ensure safe and efficient operations, the following major repairs or upgrade projects took place:
- Plant 3 upgrade design - $590,000
- Water treatment plant pump upgrades - $53,000
- Raw water intake - $36,000
- UV upgrade - $24,000
- Intake building rehabilitation - $130,000
System infrastructure
- Virgil Elevated Tank rehabilitation - $46,000
- Thorold South Elevated Tank rehabilitation - $405,000
- St. David's Standpipe decommissioning - $50,000
- Downing transmission main - $75,750
- St. David's watermain - $18,000
Notices Submitted
| Incident Date | Parameter | Result | Unit of Measure | Corrective Action | Corrective Action Date |
|---|---|---|---|---|---|
| NIL |
Water Quality Test Results
Starting in 2018, reported units of measure have been updated to match the units of measure included within Ontario Regulation 169/03 - Ontario Drinking Water Quality Standards.
Reported results that are shown with a less than symbol (<) before the value indicates that the sample result is below the lowest possible detection limit for the parameter.
Microbiological
Total Coliform and E.coli bacteria tests are performed on raw, treated and distributed drinking water.
Microbiological testing done under the Schedule 10, 11 or 12 of Regulation 170/03, during this reporting period.
| Test | Number of Samples | Range of E.Coli or Fecal Results (minimum number)-(maximum number) | Range of Total Coliform Results (minimum number)-(maximum number) | Number of HPC* Samples | Range of HPC Results (minimum number)-(maximum number) |
|---|---|---|---|---|---|
| Raw | 52 | 0-4 | 0-5,000 | Not applicable | Not applicable |
| Treated | 156 | 0-0 | 0-0 | 156 | 0-11 |
| Distribution | 270 | 0-0 | 0-0 | 270 | 0-6 |
*HPC (heterotrophic plate count) bacteria indicate biological growth. They are not harmful to humans and do not represent poor drinking water quality.
Operational
Operational testing done under Schedule 7, 8 or 9 of Regulation 170/03 during the period covered by this Annual Report.
| Test | Number of Samples | Range of Results (minimum number)-(maximum number) |
|---|---|---|
| Turbidity | 8760 | 0.017-0.191 NTU* |
| Chlorine | 8760 | 058-1.57 mg/L |
| Fluoride | Not applicable |
*NTU (nephelometric turbidity units) is a unit that measures the lack of water clarity.
An analyzer continuously monitors the water treatment process and records results on a predetermined frequency. Continuous monitors use 8760 as the number of samples.
Summary of additional testing and sampling carried out in accordance with the requirement of an approval, order or other legal instrument.
| Date of legal instrument issued | Parameter | Date Sampled | Result | Unit of Measure |
|---|---|---|---|---|
| Municipal Drinking Water Licence: August 2, 2019 | Total Suspended Solids (to environment) | Weekly Annual Average | 9.0 | mg/L |
| Municipal Drinking Water Licence: August 2, 2019 | Free Chlorine Residual (to environment) | Weekly | 0.00-0.01 | mg/L |
Inorganics
Inorganic substances include heavy metals and dissolved minerals that may be present in treated drinking water. The following is a summary of inorganic parameters tested or the most recent sample results.
| Parameter | Sample Date | Result Value | Unit of Measure | Exceedance |
|---|---|---|---|---|
| Antimony | Nov. 4, 2020 | <0.0005 | mg/L | 0 |
| Arsenic | Nov. 4, 2020 | <0.001 | mg/L | 0 |
| Barium | Nov. 4, 2020 | 0.018 | mg/L | 0 |
| Boron | Nov. 4, 2020 | 0.018 | mg/L | 0 |
| Cadmium | Nov. 4, 2020 | <0.0001 | mg/L | 0 |
| Chromium | Nov. 4, 2020 | 0.001 | mg/L | 0 |
| Lead* | - | - | - | - |
| Mercury | Nov. 4, 2020 | <0.0001 | mg/L | 0 |
| Selenium | Nov. 4, 2020 | 0.0013 | mg/L | 0 |
| Sodium | Dec. 9, 2020 | 9.93 | mg/L | 0 |
| Uranium | Nov. 4, 2020 | <0.001 | mg/L | 0 |
| Fluoride | Dec. 9, 2020 | 0.06 | mg/L | 0 |
| Nitrite | Dec. 9, 2020 | <0.05 | mg/L | 0 |
| Nitrate | Dec. 9, 2020 | 0.28 | mg/L | 0 |
*Only for drinking water systems testing under Schedule 15.2; this includes large municipal non-residential systems, small municipal non-residential systems, non-municipal seasonal residential systems, large non-municipal non-residential systems, and small non-municipal non-residential systems.
Summary of lead testing under Schedule 15.1 during this reporting period
(applicable to the following drinking water systems; large municipal residential systems, small
municipal residential systems, and non-municipal year-round residential systems)
| Location Type | Number of Samples | Range of Lead Results (min to max) | Unit of Measure | Exceedance |
|---|---|---|---|---|
| Plumbing | 4 | <0.0001 | mg/L | 0 |
| Distribution | 4 | <0.0001 | mg/L | 0 |
Organics
Trace organic test parameters include: volatile organic substances, pesticides, solvents, dioxins, PCB's, and disinfection by-products. The following is a summary of organic parameters tested or the most recent sample results.
| Parameter | Sample Date | Result Value | Unit of Measure | Exceedance |
|---|---|---|---|---|
| Alachlor | Nov. 4, 2020 | <0.000228 | mg/L | 0 |
| Atrazine + N-dealkylated metabolites | Nov. 4, 2020 | <0.0005 | mg/L | 0 |
| Azinphos-methyl | Nov. 4, 2020 | <0.000171 | mg/L | 0 |
| Benzene | Nov. 4, 2020 | <0.0001 | mg/L | 0 |
| Benzo(a)pyrene | Nov. 4, 2020 | <0.00001 | mg/L | 0 |
| Bromoxynil | Nov. 4, 2020 | <0.0000195 | mg/L | 0 |
| Carbaryl | Nov. 4, 2020 | <0.001 | mg/L | 0 |
| Carbofuran | Nov. 4, 2020 | <0.002 | mg/L | 0 |
| Carbon Tetrachloride | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| Chlorpyrifos | Nov. 4, 2020 | <0.000171 | mg/L | 0 |
| Diazinon | Nov. 4, 2020 | <0.000171 | mg/L | 0 |
| Dicamba | Nov. 4, 2020 | <0.000195 | mg/L | 0 |
| 1,2-Dichlorobenzene | Nov. 4, 2020 | <0.0003 | mg/L | 0 |
| 1,4-Dichlorobenzene | Nov. 4, 2020 | <0.0003 | mg/L | 0 |
| 1,2-Dichloroethane | Nov. 4, 2020 | <0.0003 | mg/L | 0 |
| 1,1-Dichloroethylene (vinylidene chloride) | Nov. 4, 2020 | <0.0003 | mg/L | 0 |
| Dichloromethane | Nov. 4, 2020 | <0.001 | mg/L | 0 |
| 2-4 Dichlorophenol | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| 2,4-Dichlorophenoxy acetic acid (2,4-D) | Nov. 4, 2020 | <0.00065 | mg/L | 0 |
| Diclofop-methyl | Nov. 4, 2020 | <0.00013 | mg/L | 0 |
| Dimethoate | Nov. 4, 2020 | <0.000171 | mg/L | 0 |
| Diquat | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| Diuron | Nov. 4, 2020 | <0.006 | mg/L | 0 |
| Glyphosate | Nov. 4, 2020 | <0.02 | mg/L | 0 |
| HAA | Running annual average | 0.013 | ||
| Malathion | Nov. 4, 2020 | <0.000171 | mg/L | 0 |
| 2-Methyl-4-chlorophenoxyacetic acid (MPCA) | Nov. 4, 2020 | <0.0065 | mg/L | 0 |
| Metolachlor | Nov. 4, 2020 | <0.000114 | mg/L | 0 |
| Metribuzin | Nov. 4, 2020 | <0.000114 | mg/L | 0 |
| Chlorobenzene | Nov. 4, 2020 | <0.0005 | mg/L | 0 |
| Paraquat | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| Pentachlorophenol | Nov. 4, 2020 | <0.0003 | mg/L | 0 |
| Phorate | Nov. 4, 2020 | <0.000114 | mg/L | 0 |
| Picloram | Nov. 4, 2020 | <0.000091 | mg/L | 0 |
| Polychlorinated Biphenyls(PCB) | Nov. 4, 2020 | <0.00006 | mg/L | 0 |
| Prometryne | Nov. 4, 2020 | <0.000057 | mg/L | 0 |
| Simazine | Nov. 4, 2020 | <0.000171 | mg/L | 0 |
| THM | Running annual average | 0.022 | ||
| Terbufos | Nov. 4, 2020 | <0.000114 | mg/L | 0 |
| Tetrachloroethylene | Nov. 4, 2020 | <0.0003 | mg/L | 0 |
| 2,3,4,6-Tetrachlorophenol | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| Triallate | Nov. 6, 2019 | <0.000114 | mg/L | 0 |
| Trichloroethylene | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| 2,4,6-Trichlorophenol | Nov. 4, 2020 | <0.0002 | mg/L | 0 |
| Trifluralin | Nov. 4, 2020 | <0.00014 | mg/L | 0 |
| Vinyl Chloride | Nov. 4, 2020 | 0.0001 | mg/L | 0 |
Any Inorganic or Organic parameter(s) that exceeded half the standard prescribed in Schedule 2 of Ontario Drinking Water Quality Standards.
| Parameter | Result Value | Unit of Measure | Date of Sample |
|---|---|---|---|
| Sodium | 9.9-16.2 | mg/L | Jan. 15, 2020, Feb. 12, 2020, Feb. 26, 2020, March 13, 2020, April 7, 2020, May 6, 2020, May 13, 2020, June 3, 2020, Julu 8, 2020, Aug. 5, 2020, Aug. 19, 2020, Sept. 23, 2020, Oct. 28, 2020, Nov. 4, 2020, Dec. 9, 2020* |
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