Mission Bay, Riviera Shores is a saltwater beach in San Diego County, California. Across 75 bacteria samples collected between 2022 and 2025 at nearby monitoring stations, it earns a Beach Safety Grade of F — Failing.
About 81% of samples at Mission Bay, Riviera Shores exceeded the EPA Beach Action Value of 104 CFU/100 mL for Enterococcus — the threshold at which water managers typically post a swimming advisory. In practice that means the safe-swimming limit was frequently crossed here over the monitored period. Bacteria samples exceed the safe-swimming threshold a large share of the time — this beach flags advisories often.
The evidence behind this grade is deep for a beach page: 75 results from 2 monitoring stations, spanning 2022 to 2025. Enough sampling, from enough places, over enough seasons that one bad week can't drive the letter.
Mission Bay, Riviera Shores is currently listed as inactive in the EPA beach-monitoring program, so it may no longer be routinely sampled. Its grade reflects the water-quality results collected while it was active — useful history, but confirm the beach's current status and any local advisory before you visit.