American Water Resources Association 2016 ANNUAL WATER RESOURCES CONFERENCE November 14‐17, 2016 Orlando, FL Thursday, Nov. 17 8:30 AM – 10:00 AM SESSION 70: Water Quality: Bacteria Evidence‐based Guidelines for Microbial Source Tracking Projects ‐ James Herrin, Source Molecular Corporation, Miami, FL Fecal bacteria carried by nonpoint sources are often difficult to track. Microbial source tracking (MST) techniques are used to analyze water samples and find the source of fecal bacteria. Correctly identifying the source of fecal contamination has a big impact in formulating remediation plans. The presentation will detail lessons learned and outcomes achieved from two MST projects. We will provide evidence‐based guidance on crafting an effective MST plan. 1. Tower Road Bayside Beach in Delaware suffered from consistently high counts of Enterococcus. The persistent pollution prompted the Department of Natural Resources and Environmental Control to conduct a source tracking study in summer 2011. Watershed managers wanted to know if humans, dogs or seagulls were the main contributors of the high fecal bacteria levels measured at the beach. From May to September 2011, beach managers collected samples three times weekly at different locations along the shoreline, totaling 49 samples. Source Molecular Corporation and Dr. Jody Harwood of the University of South Florida tested the samples for DNA of bacteria from human and gull feces. Source Molecular also tested the samples for specific dog‐associated and bird‐associated fecal bacteria. Both labs identified seagulls as the major contributor of fecal contamination observed at Tower Road Bayside Beach. The results indicated seagull‐associated bacteria dominated in 98% of the water samples. In contrast, human and dog bacteria were only detected in 19% and 4% of the samples, respectively. These data confirmed the project proponents' visual observations that seagulls contributed to the elevated levels of Enterococcus at the beach. 2. High levels of E. coli were observed in segments of the San Juan and Animas Rivers flowing into northern New Mexico. The San Juan Watershed Group (SJWG) decided to find out where the fecal bacteria originated. The conservation group worked with Source Molecular Corporation and Dr. Geoffrey Smith from New Mexico State University to conduct a 2‐year MST study. From April to October 2013 and 2014, watershed managers collected weekly water samples from five sites on the Animas and San Juan Rivers. They wanted the water samples to be tested for Human, Cow, Ruminant (deer, elk, cows, sheep), and Bird fecal bacteria DNA. Water samples were also collected for E. coli and nutrient analyses. Fecal bacteria associated with human and ruminant feces were detected in 77% and 94% of water samples, respectively. Fecal contamination from these sources was detected at all five sites tested. Human source bacteria was a bigger problem on the San Juan than on the Animas. The human fecal bacteria results were confirmed by additional analyses performed in Dr. Jody Harwood's lab. The main source of human pollution was septic systems and the SJWG initiated efforts to educate local governments about regulatory options to enforce septic system monitoring and maintenance. SJWG also increased outreach efforts to septic disposal contractors and, as a result, all area contractors are now certified by the state. Future plans include continued monitoring to see if the human sourced bacteria decreased as a result of these actions. Bacteria Monitoring in Near‐Shore Waters at Florida Beaches: Case Studies of Frequency and Duration of High‐Bacteria Events – L. Donald Duke, Florida Gulf Coast University, Fort Myers, FL (co‐authors: A. K. Will, C. L. Tretter) Near‐shore waters where beaches promote contact recreation in the U.S. are monitored for bacteria by state‐level programs, supported by funding and guidance from U.S. EPA. In Florida, the Department of Health (FDOH) monitors some 250 beaches in 30 counties, and reports resulting data on a public web site. EPA guidance specified once‐weekly sampling until 2013, after which it provided funds for only bi‐weekly sampling. Monitoring data are used by counties to post advisories against human contact when numeric targets are exceeded for fecal indicator organisms (FIOs). Over the course of years, the same data can be analyzed for temporal and spatial trends and relationships. This research used publicly‐available FDOH data to investigate reported exceedances and advisories for 17 beaches, in 9 counties distributed along Florida's coast, collected weekly over about 9 years (January 2004 ‐ October 2012), for a total of over 500 sampling events at each target beach. The research selected, in each target county, two beaches with the greatest number of exceedances ‐ not spatially representative of the Florida coastline, but those where FIOs were most frequently reported in excess of numeric guidelines over the target period. The objectives were to identify any apparent trends in frequency of exceedences across a wide geographic range, determine whether these worst‐case beaches exceed targets sufficiently often to be of concern, and assess any factors that might lead to suggested improvements in the monitoring strategy. Results showed substantial variation among beaches: five of 17 analyzed beaches showed exceedances in fewer than 8% of all weeks sampled; three others showed exceedances in more than 30% of weeks sampled. Most (nine beaches) were in the 10% ‐ 20% range. These beaches were selected to be among those with the highest frequency of exceedence in Florida, so we conclude only that some beaches experience high‐bacteria episodes frequently enough to be of concern. A second analysis used re‐sampling data to broadly approximate duration of those episodes over the target period, taking advantage of guidelines that call for counties to collect samples within a few days of any test showing FIOs exceeding numeric targets. For 13 beaches in aggregate, re‐samples suggest most (>60%) episodes persist for 2 days or less. At four beaches assessed in detail, each beach showed about half of the episodes persisting for 2 days or less; only about 25% persisted for seven days or more. That finding suggests that, during this 9‐year period, sampling at a 7‐day repeat interval may have failed to detect a substantial number of instances when FIO concentration exceeded health‐based guidelines. Quantitative Relationship between Environmental Factors and Bacteria in Near‐Shore Marine Waters, Sarasota County, FL ‐ Jennifer Clemente, FL Dept of Health in Sarasota County, Venice, FL (co‐author: L. D. Duke) This research analyzes data on bacteria in near‐shore ocean waters in Sarasota County, Florida to identify temporal patterns, spatial patterns, and potential environmental causal factors for enterococcus and fecal coliform bacteria, collected in the surf zone at 16 recreational beaches over 10 years (2001‐2011) by Florida Department of Health (FDOH's). FDOH's purpose, to identify times when contact with water could be unhealthful and advise against beach swimming at those times, is compromised natural fluctuations more rapid than the four‐day time from sampling to posting, and could benefit with improved understanding about environmental conditions when potentially unhealthful concentrations experience increased likelihood. The objective of this research is to identify any environmental, temporal, or geographical factors that can be quantitatively associated with the presence or magnitude of enterococcus or fecal coliform bacteria in near‐shore marine waters. Research of this kind is hampered by the relatively small number of cases where bacteria occurred in high enough concentrations to be detected by available methods. So many of the sample events returned non‐detectable amounts that correlations were inconclusive in the face of high natural variation in the data. A possible response is to aggregate data across multiple beaches, but this research showed the 16 beaches in close physical proximity varied in bacteria data's frequency, distribution, seasonality, and relationship to environmental factors that it is not valid to treat them as a single statistical sample. The data do not have a normal distribution, and could not be transformed into a normal distribution with any logarithmic or other transformation we could identify, so nonparametric analyses were used for these data. Most of the findings were made using the frequency of detected high concentrations, as no quantitative associations were found with variation in magnitude. The most strongly associated component was tidal conditions ‐ both tide stage and tide level. Of all exceedances over 10 years at 16 beaches, 62% occurred during flood stage (as opposed to 16% during ebb, 23% during slack stages). About 43% of exceedances occurred during high tide level, with a very similar 42% occurring in "middle" level, and only 14% at low tide. However, assessing beaches individually showed sharply varying results: for example, Venice Fishing Pier beach experienced far more exceedances during high tide, and Ringling Causeway beach showed an almost equal distribution across all 3 stages, demonstrating that other factors promote bacteria there. Surprisingly, the amount of precipitation in periods preceding sampling did not show quantitative association with either frequency or magnitude of bacteria in samples, even though the beaches' catchments are relatively small. This was largely true when testing for a wide range of antecedent periods (1, 2, 7, 10, and 30 days). In this factor also, results varied among locations: at Brohard Beach, 36% of samples following high 1‐day rainfall were exceedances; at Longboat Key, most exceedances occurred when rainfall was very high in the preceding 30 days. There was also little quantitative relationship when considering these factors in conjunction. Assessment of Bacteria Sources Allocation and Conservation Practices for Water Quality Enhancement in Arroyo Colorado Using SWAT Model ‐ Jaehak Jeong, Texas A&M AgriLife Research, Temple, TX (co‐authors: Y. Her) The Arroyo Colorado is an ancient distributary channel formed by the Rio Grande River. The Arroyo Colorado is 90 miles long and flows through Hidalgo, Cameron and Willacy counties of Deep South Texas and ultimately flows into the Lower Laguna Madre. The Arroyo Colorado has been included on Texas' list of impaired water bodies (Clean Water Act Section 303(d) List) due to the occurrence of low dissolved oxygen (DO) and high levels of bacteria in the tidally‐
influenced portion of the stream. A model setup of the Soil and Water Assessment Tool (SWAT) watershed model was developed to simulate flow and selected water quality parameters for the Arroyo Colorado watershed (ACW). The model simulates flow, transport of sediment and nutrients, water temperature, dissolved oxygen, and bacteria load (i.e. E. coli). The model was calibrated and tested for flow with data measured during 2000‐2009 at two streamflow‐gaging stations. The flow was calibrated satisfactorily at monthly and daily intervals. In addition, the model was calibrated and tested sequentially for suspended sediment, orthophosphate, ammonia nitrogen, water temperature, dissolved oxygen, and e. coli concentration. The simulated loads or concentrations of the selected water quality constituents generally matched the measured counterparts available for the calibration and validation periods. Landuse change scenario was simulated for the year 2025 after estimation of land cover maps, which mainly address a rapid expansion of urban lands (12%). The scenarios were intended to identify a suite of best management practices (BMPs) to address the depressed DO and high levels of bacteria problems in the watershed. Calibrated/validated parameters were transferred to these projected datasets and BMPs requirements were assessed with which the water quality meets the DO/bacteria requirements under the projected land use change. Continuous Monitoring for Harmful Algal Blooms – Stephanie A. Smith, YSI, Yellow Springs, OH Harmful algal blooms (HABs) are becoming one of the greatest threats to surface waters in the world. The term “bloom” refers to a rapid and visible overgrowth of algae, ranging from freshwater blooms of blue‐green algae to diatoms and dinoflagellates associated with red tides. The “harm” comes in the production of toxins that are known to impact animal and human health, and in a rapid decline of dissolved oxygen, which can lead to massive fish kills and other detrimental effects on the ecosystem. For surface water managers, especially managers of recreational and drinking water sources, the key to managing a HAB event is early detection. However, there are relatively limited tools for doing this, and we will compare advantages and limitations of the most common approaches. YSI’s total algae (TAL) sensors are among these, and are the best tool available to provide an early warning of the onset of a bloom. This enables better management and potentially even mitigation of a bloom event. However, users must understand what the TAL sensors are measuring and more critically, what they are not measuring, to realize their full potential for this application. When combined with measurements of other parameters relevant to HAB monitoring, such as pH, dissolved oxygen, turbidity, and temperature, the TAL sensors are part of a powerful platform for monitoring and managing HAB events.