A west Edmonton stormwater pond that saw controversy last year over its use of a chemical to eradicate invasive goldfish species is once again facing the same issue. The pond in Guinevere Park has been the target of treatments, including a chemical called rotenone, to cull invasive species for the second year in a row, according to Edmonton-based utility EPCOR. EPCOR is responsible for the city’s drainage system and works with Alberta Environment and Protected Areas (AEPA) to keep stormwater and runoff bodies of water free from invasive species, like goldfish or Prussian carp. This year, the company told CTV News Edmonton the largest goldfish they’ve removed from a pond so far has been 33 cm long and 1.4 kg. The body of water on 69 Avenue NW, which EPCOR refers to as a stormwater pond, is one of four out of 240 EPCOR-owned ponds the company treated this year for invasive species of fish. Rotenone was used in each case. An email from EPCOR media relations confirmed that each year, affected ponds are treated in two rounds. The second round of treatment is to eradicate any invasive fish that could have hatched after the first treatment. “Rotenone is a plant-based, naturally-occurring organic chemical compound … It’s approved by Health Canada for its intended use, and it breaks down naturally in the water and has no long-term adverse effects,” said Abhishek Bhargava, the senior manager with EPCOR water services, in an interview Wednesday. While the chemical has been used to treat EPCOR’s stormwater ponds for the last six years, last year saw pushback, Bhargava added. “Right now, the residents of the neighborhood, from what I hear, just want EPCOR to be done and out of here,” said a spokesperson for a group of concerned residents, Gary Boehm, on Thursday. “It’s been very disruptive to people’s lives, very upsetting to a lot of people … the application that they did last year was unsuccessful, so they had to come back and do it again.” Last year’s treatment was delayed when AEPA asked EPCOR to pause the use of rotenone after hearing concerns from a group of residents about fenced-off areas of water and chemical complaints. “The two things we were worried about were the health impacts, but also the impacts to the environment,” Boehm said. “We also looked at this [area] as a wetland. We wanted to preserve the wetland.” Because of the delay in chemical treatment, EPCOR was only able to do one round of rotenone last year, much later in the season, when it was colder. “This year was just perfect, with the dry and sunny weather,” Bhargava said. He added that rotenone is used to kill anything with gills. A report from the company Boehm was able to get through a Freedom of Information and Protection of Privacy request and sent to CTV News Edmonton said a total of 1,499 kg (just over 3,300 lbs) of Prussian carp and invasive goldfish species were removed last year from Edmonton water. Nearly 98,000 fathead minnows, which are not invasive, were also killed off, which Boehm takes issue with. “We want those restored. We want the ecosystem restored … we thought we had an agreement with EPCOR on that, with [AEBA],” he said. Bhargava said it’s a regulatory requirement that EPCOR remove invasive species – and an email from the company’s media relations to Boehm confirmed that they’re not responsible for populating the stormwater management facilities they own with fish. That’s because, they explained, the ponds are “operational facilities” where EPCOR adjusts water levels and makes other changes for maintenance reasons. The second round of treatment for this pond happens Monday, and officials say they’re hopeful not to have to return next year. In the meantime, the minister’s office for the environment and protected areas of Alberta sent a statement to CTV News Edmonton on Thursday, saying invasive fish species like koi, carp and goldfish need to be removed and prevention is the best option. “Never release any aquarium pets, water garden plants, live food or live bait into rivers, streams, lakes, ponds or storm sewers,” it read. “Releasing these fish into any body of water outside of an aquarium or fish tank is illegal.”