CSA Ocean Sciences Inc. (CSA) has been providing services for the Puerto Rico Aqueduct and Sewer Authority (PRASA) since 1999 under subcontract to CH2M Hill, Inc. CSA is performing comprehensive environmental monitoring, including both biological and chemical field sampling and data collection for 301(h) waiver demonstrations and mixing zone validation studies at the Aguadilla, Arecibo, Bayamon/Puerto Nuevo, Carolina, and Ponce Regional Wastewater Treatment Plant (RWWTP) outfalls offshore Puerto Rico. Initially, CSA scientists coordinated with U.S. Environmental Protection Agency (EPA) staff relative to station location and sampling methodologies and assisted in the preparation of the Quality Assurance Project Plan (QAPP).
During the 14-year span, the studies evolved from requiring quarterly sampling to requiring the bi-annual collection of influent, effluent, receiving water, sediment, and fish/epifaunal samples.
CSA collects sediment grab samples using a 0.04-m2, Teflon-coated, non-contaminating modified Van Veen grab to characterize sediment quality (i.e., grain size, total organic carbon, total phosphorus, and total Kjeldahl nitrogen) and benthic invertebrate communities. Fish sampling is conducted around the outfalls at all sites using baited Antillean “Z” traps and hook-and-line methods for population, bioaccumulation, and health studies. Sediment chemistry samples are collected annually using a modified Van Veen grab. Samples are analyzed for metals, pesticides, polychlorinated biphenyls, dioxin, asbestos, fluoride, sulfide, total nitrogen, total phosphorus, total Kjeldahl nitrogen, BTEX (benzene, toluene, ethylbenzene, and xylenes), volatile organic compounds, polycyclic aromatic hydrocarbons, and other organic compounds. Additional tasks include the semi-annual characterization and monitoring of coral, fish, and epibenthic community stations using repetitive permanent video transects, still photography quadrats, and random video transects. CSA staff assist CH2M Hill in the receiving water collection procedures, employing EPA Method 1669 for clean sampling techniques. Receiving water samples were initially collected using pre-cleaned, Teflon®-lined vacuum tubing and a non-contaminating peristaltic pump, but have more recently been collected using pre-cleaned, Teflon®-coated water bottle arrays.
Since 2006, CSA also has conducted various 403(c) waiver demonstrations, bacteria mixing zone, and dye studies to map effluent at the Aguadilla, Arecibo, Barceloneta, Bayamon/Puerto Nuevo, Carolina, Humacao, and Mayaguez RWWTP outfalls. Additionally, the surveys monitor sediment quality and chemistry, benthic invertebrate communities, fish and epibenthic invertebrate communities, fish bioaccumulation, and coral communities using the methods previously described.
More recently, CSA has conducted remotely operated vehicle and diver-held video surveys to inspect and document the integrity of diffusers and/or outfalls at the Ponce and Bayamon/Puerto Nuevo outfall sites. All survey reports and the results of the video and still photography data analyses have been submitted to CH2M Hill, and final reports are submitted to both the EQB and EPA.