Ongoing climate change and urbanization will continue to put pressure on diminishing freshwater resources. To combat these effects, water management policies need to be continually updated with the most current scientific information to reflect changes in types and amounts of pollutants and new knowledge about toxicity. For this analysis, we compared two metals: a well-studied pollutant (copper [Cu]) and emerging contaminant of concern (silver [Ag]). We assessed water quality criteria for these two metals from the United States, Australia and New Zealand, South Africa, Canada, and the European Union to determine the intent of these criteria and implementation strategies used in adoption practices. Additionally, we conducted standard chronic toxicology tests for silver and copper on the freshwater pond snail Lymnaea stagnalis to assess the level of effectiveness offered by each regulation in protecting ecological integrity. L. stagnalis were individually placed in 100 mL beakers of test solution (0–32 µg/L for both Cu and Ag) for a 28-day period with water changes every 4 days. Ten replicates were used per treatment to measure mortality and growth rates. Preliminary results suggest that Ag is more toxic than Cu. However, because Ag is a poorly studied contaminant, water quality criteria for Ag are typically older, more variable, or absent and thus may not offer protection in some jurisdictions.