Lake Elsinore & San Jacinto Watersheds Authority (LESJWA) is informing the Canyon Lake community that doses of alum (aluminum sulfate) will be applied to the lake in the main body, east bay and the area north of the causeway from Apr. 15 through Apr. 19.
Stormwater runoff carries with it high levels of nutrients including nitrogen and phosphorus that hurt water quality and threaten aquatic life. This dose will be the 12th Canyon Lake alum application that has taken place.
Alum, the method selected to provide the best results for Canyon Lake, has a proven track record of success and is safe to both humans and aquatic life. Drinking water quality will not be affected by any of the treatment options. Canyon Lake will remain open during the entire treatment process. Recreational users will experience little disruption during treatment application and implementation.
In order to comply with water quality regulations enforced by the state, through the local Santa Ana Regional Water Quality Control Board, the Lake Elsinore & Canyon Lake Nutrient Total Maximum Daily Load (TMDL) Task Force utilizes local stakeholder funding to continue alum water treatments in Canyon Lake. The TMDL Task Force evaluated several options during the CEQA process and determined that alum application provides the best option as a step to effectively treat the entire lake in a timely manner with minimal impact to Canyon Lake residents.
The alum schedule is as follows (subject to change due to inclement weather):
- Monday, Apr. 15: Main Body, 7 a.m to 4 p.m.
- Tuesday, Apr. 16: Main Body, 7 a.m. to 4 p.m.
- Wednesday, Apr. 17: Main Body, 7 a.m. to 4 p.m.
- Thursday, Apr. 18: East ramp/north causeway, 7 a.m. to 4 p.m.
- Friday, Apr. 19: Clean-up
Questions and answers about the treatment, supplied by LESJWA:
Q: What is alum?
A: Alum is one of the most common minerals found on earth and has been used since Roman times for water purification. Alum is a common ingredient in cosmetics, antiperspirants, toothpaste, bath salts and antacids. It is sold as a spice in most grocery stores.
Q: Will alum affect the drinking water quality of Canyon Lake?
A: No. Aluminum concentrations in the lake itself will meet the Public Health Goal for aluminum in finished drinking water within 24 hours following the alum application.
Q: Will my use and access of the lake be impacted by the water treatment?
A: Recreational users will experience minimal disruption during treatment application and implementation.
Q: Will boats be allowed on the lake during the application?
A: Yes, but certain areas of the lake will be blocked off during the application process which should last only a few hours. Boats will have full lake access immediately after the application process is completed.
Q: Will beaches be closed during the application? Will it be safe to swim?
A: Some areas might be briefly closed off during the alum application, but access will be open immediately once the application process is completed. Swimmers will be able to safely enjoy the lake immediately after the application process is complete.
Q: Will fishermen be allowed to fish during the application? Are the fish safe to eat?
A: Yes, but certain areas of the lake will be blocked off during the application process which should last only a few hours. Fishermen will have full lake access immediately after the application process is completed.
Q: Will there be any visual impacts with the water treatment?
A: No. In fact, Canyon Lake’s water clarity should improve immediately once the alum is applied.
Q: Will boating be allowed?
A: Yes. We are going to allow boating, but under a yellow status (5 mph) and no skiing or wakeboarding because of the lower speed.
Q: Can we go in the water immediately after the treatment?
A: Yes, it’s the same as bath salts. To give an idea, it’s about the equivalent of one aspirin to 25 gallons of water. It’s no more toxic than holding a penny.
Q: Will fish have a response?
A: None whatsoever. If you see a dead fish in the water afterward, it died of natural causes.
For daily operational updates, visit canyonlakealum.wordpress.com. A video of the alum application can be viewed at https://youtu.be/D0iUtkTVGnc. For more information, contact Mark Norton at Lake Elsinore & San Jacinto Watersheds Authority at 951-354-4221 or MNorton@sawpa.org.