Application of Same-Day Enterococcus qPCR-Based Analyses for Quality Assessment of Shorelines (Water and Sand) at Recreational Beaches

Rapid water-quality monitoring methods for beach water and sand can be helpful public health authorities to develop comprehensive programs. In this study, we evaluated the performance of Enterococcus qPCR (USEPA 1609.1) method quality sand-porewater at two Niagara region beaches in Ontario, Canada (Lakeside Sunset Beaches). While USEPA 1609.1 has been validated water, its potential assessing associated sands (which may function as a microbial reservoir) not fully explored. All samples (n = 168) passed control (QC). However, only 20 out 48 (41.7%) QC, potentially due interference by soluble inhibitors. The proportion passing QC improved slightly 63 120 (52.5%) with prefiltration step remove other large particles. faecal indicator density sand-porewater, tested parallel, did correlate density. Comparing data same-day threshold previous-day E. coli culturing-based across all days tested, analyses identified 3 (7%) 7 (16%) false positive/lost Lakeside Beaches, respectively. Additionally, total 2 (5%) 1 (2%) negative/health-risk Sand-porewater testing when indicators (in sand) exceeded thresholds. Compared conventional culturing, use would result fewer postings could identify several additional health-risk (when posted). Future studies include steps or modifications protocol improve method’s applicability monitoring.