VANCOUVER, British Columbia, April 22, 2025 – waterStrider Treatment Inc. (“waterStrider”), today announced its repeated breakthrough success to remove dissolved selenium from mine impacted water. waterStrider’s patent-pending Amprey™ electrochemical technology most recently reduces dissolved selenium (in parts per billion or “ppb”) from 207 ppb to below 0.5 ppb, which is greater than 99.8% removal. This water was formulated to imitate water at a uranium mine in Northern Saskatchewan.
This latest breakthrough builds on previous results and further reinforces the effectiveness of waterStrider’s approach across several key performance areas:
- Over 99.8% selenium removal and over 99.9% removal of a broad range of contaminants
- The solid waste by-product is non-leachable for selenium and all regulated metals
- Speciation analysis confirmed over 99% of selenium in source water was present as hard-to-remove selenate, which was successfully converted to a treatable form and removed
“waterStrider’s proprietary treatment technologies effectively remove a wide range of contaminants — including particularly challenging ones like selenium, sulphate, and nitrate — from mine-impacted water, delivering significant operational and environmental benefits. Our system allows mine operators to address all their water treatment needs with a single solution, reducing both capital and operating costs,” stated Andriyko Herchak, waterStrider CEO.
In November 2024, waterStrider first reported its major breakthrough from a different mine water sample, reducing dissolved selenium from 116 ppb to just 0.42 ppb. These results for selenium are well below the B.C. Water Quality Guidelines discharge limit of 2.0 ppb, and the U.S. Environmental Protection Agency limits of 1.5 ppb (still water) and 3.1 ppb (moving water) for most surface waters in the U.S.
1. Removing Selenium and Other Contaminants
This recent testing, conducted in March 2025 at waterStrider’s pilot facility in Vancouver, B.C., reconfirmed that Amprey's electrochemical process effectively dissolves metal pellet anodes to facilitate selenium reduction for co-precipitation with iron.
waterStrider’s technologies are scalable to treat mine-impacted water containing dissolved selenium, offering significantly lower capital and operating costs compared to other treatment methods. waterStrider’s process also effectively removes a broad range of other dissolved metals and contaminants of concern, including nitrate and sulphate, and all were removed well below B.C. discharge limits.
The following Table shows a sample of the testing results performed by an accredited independent lab. The less-than “ < ” amounts represent below lab detection limits:
| Dissolved Contaminant |
Feed Water (ppb) |
Best Treated (ppb) |
Percent Removal |
| Arsenic | 281 | < 0.5 | > 99.8% |
| Cadmium | 93.4 | < 0.02 | > 99.9% |
| Cobalt | 3,910 | < 0.5 | > 99.9% |
| Iron | 318,000 | < 20 | > 99.9% |
| Lead | 580 | < 0.25 | > 99.9% |
| Selenium | 207 | < 0.5 | > 99.8% |
| Zinc | 9,110 | < 5 | > 99.9% |
| Nitrate | 3,540 | < 1,000 | > 71.8% |
| Sulphate | 3,240,000 | 887,000 | 72.60% |
2. Metals Removed Do Not Leach
The solid waste by-product is readily dewaterable, small in volume, and chemically stable - it does not leach. This provides major advantages over other mine water treatment systems that use lime or microorganisms, which produce large volumes of chemically unstable solid waste by-products that leach high concentrations of toxic contaminants back into the environment, adding to costs and liabilities.
The solid waste by-product from the March 2025 testing underwent standard and regulated Toxicity Characteristic Leachate Procedure (TCLP) testing, to test for selenium and other regulated metals. The following table shows a sample of the testing results, which were performed by an accredited independent lab. “B.C. Limit” in the Table below is the B.C. Hazardous Waste Legislation & Regulations Leachate Quality Standards Concentration in Waste Extract. The less-than “ < ” amounts represent below lab detection limits:
| Metal Regulated for Leaching in B.C. | Metal Concentration Before TCLP Test (mg/kg dry) | Amount of Metal that Leached (mg/L) | B.C. Limit for Leaching (mg/L) | waterStrider Below B.C. Limit (%) |
| Arsenic | 7.27 | <0.010 | 2.5 | > 99.6% |
| Cadmium | 1.78 | <0.001 | 0.5 | > 99.8% |
| Copper | 628.5 | <0.10 | 100 | > 99.9% |
| Lead | 5.245 | <0.010 | 5 | > 99.8% |
| Nickel | 145.45 | <0.10 | 500 | > 99.9% |
| Selenium | 4.525 | <0.020 | 1 | > 98.0% |
| Uranium | 1.21 | <0.020 | 10 | > 99.8% |
| Zinc | 77.75 | <0.50 | 500 | > 99.9% |
3. Selenium Speciation Testing
In mine-impacted waters, selenium is generally present in its oxidized form as hexavalent selenium or “selenate”. Since selenate cannot be efficiently removed by water treatment methods, selenate must be chemically altered to reduced forms of selenium.
In the March 2025 testing, the selenium in the feed water was greater than 99% in the form of selenate (selenium, hexavalent, Se VI). waterStrider’s mine water treatment process converted selenate to reduced forms of selenium that were removed by co-precipitation with iron.
Results of selenium speciation testing that was performed at an accredited independent lab are shown in the following Table, with less-than “ < ” amounts representing below lab detection limits.
| Selenium Speciation | Feed Water (ppb) |
Treated Water (ppb) |
| Methaneselenonic acid, MeSe VI, as Se | <0.50 | <0.10 |
| Selenium species, Other, as Se | <0.10 | <0.10 |
| Selenium, hexavalent, Se VI | 220 | <0.10 |
| Selenium, tetravalent, Se IV | <0.50 | <0.10 |
| Selenocyanate, SeCN, as Se | <0.50 | <0.10 |
| Selenomethionine, SeMet, as Se | <0.50 | <0.10 |
Testing and Collaboration Opportunities Available
waterStrider is seeking to introduce our new breakthrough process to mines with elevated selenium concentrations and other difficult to remove contaminants of concern. waterStrider offers treatability testing of mine impacted water samples at our pilot facility in Vancouver, B.C. to confirm contaminant removal and provide estimates of capital and operating costs. We encourage interested mines to contact us.
To learn more about AmpreyTM, get in touch at
About waterStrider Treatment Inc.
waterStrider is a Canadian-based, privately owned cleantech company with a proven performance track record in both laboratory and relevant operational environments. Leveraging a suite of patented and patent-pending technologies, waterStrider effectively removes a broad range of dissolved metals from water such as arsenic, cadmium, cobalt, selenium, zinc, and many others, as well other contaminants including cyanide, sulphate, nitrate, nitrite.
The waterStrider solution not only delivers significant environmental and operational improvements but also does so at substantially lower capital and operating costs compared to conventional systems. Designed to perform in all climates, waterStrider technologies offer a versatile, cost-effective answer to today’s most pressing mine water treatment challenges.
For more information about the company, please contact:
Andriyko Herchak, CEO
www.waterstridertmt.com