The Recovery of MArsh Creek
Water Quality Monitoring
Marsh Creek Creosote Remediation
The long history of industrial activity in Saint John has led to immense creosote contamination in Marsh Creek sediments. Creosote is a dark oil that is used to treat wood. In some portions in the lower river the sediment is completely black, and when touched, produces a large oily sheen. This is not the kind of environment that promotes healthy aquatic life, and as the stream feeds directly into the Saint John Harbour, it is crucial that we do our best to remove it. Polycyclic aromatic hydrocarbons (PAHs) are the toxic components that make up creosote. The sediments in Marsh Creek currently have average total PAH values over 4000 mg/kg, which towers in comparison to guidelines and the reference conditions for the Saint John Harbour (Van Geest et al., 2015). In 2018 ACAP Saint John piloted a project using bioremediation techniques to degrade the hydrocarbons that make up creosote. This means that we added hydrocarbon degrading bacteria to the sediments in the stream, in hopes that it would reduce the contamination. This project will continue in coming years. We hope to see PAH levels decline dramatically and to restore Marsh Creek back to a healthy habitat for all aquatic life.
Van Geest JL, Kidd KA, Hunt HL, Abgrall MJ, Maltais MJ, Mercer A. 2015. Can. Manuscr. Rep. Fish. Aquat. Sci. 3076: v + 97 p.
Marsh Creek Water Quality Monitoring
The objective of the Marsh Creek Water Quality Monitoring project in the past was to retrieve and record as much data as possible prior to the ceasing of the raw sewage outfalls. Following the cessation of raw sewage deposition in late 2014, the objectives of the project continued, with a mind toward evaluating the recovery the water quality since this historic Harbour Cleanup milestone. Since the completion of Harbour Cleanup, the Water Quality Monitoring project has expanded into various other watersheds within the Greater Saint John area.
Water samples are repeatedly collected and tested at a number of sites over the summer field season. These tests are performed by summer students from the Chemical Technology programme at the New Brunswick Community College (NBCC). Seven different tests are performed including testing pH and dissolved oxygen in the field, and testing total fecal coliform count, orthophosphates and total suspended solids in the laboratory at NBCC.
Overall, the water quality monitoring conducted in the 2017 field season throughout the Greater Saint John area, revealed that the urban and suburban watersheds have many potential impacts that have resulted in diminished water quality in some areas; however, they are still capable of, and do, support aquatic life. The most notable impact to these urban watersheds is stormwater runoff, the potential for sanitary sewer overflows being discharged into these watercourses, and riparian degradation. All of the watersheds monitored also have areas of exemplary water quality that meet the habitat and water quality needs of aquatic species. The variance between these areas indicates that these watersheds have the potential to flourish as productive habitats and that demonstrable improvements can be made to restore the degraded areas and improve stormwater runoff and filtration.
The Marsh Creek watershed is a prime example of how reducing anthropogenic impacts into a
watercourse can lead to substantial improvements in water quality. Since the completion of
Harbour Cleanup in 2014, the Marsh Creek watershed has shown improvements year after year in terms of water quality. The dissolved oxygen concentrations have increased at all the monitoring sites this year and surpassed the Canadian Council of Ministers of the Environment guideline recommendation concentration of 6.5 mg/L on average at all the sites. Prior to the cessation of discharging sewage into this watercourse many of the impacted sites were so low in dissolved oxygen that it would not support any aquatic life; therefore, the improvement of this watercourse to a point of surpassing this guideline is a great achievement. Additionally, the fecal coliform concentration continues to decrease; however, lift station overflows still likely remain an issue within this watershed and as such only two sites were below the Health Canada guideline of an average of 200 CFU/100 mL. The concentrations found this year continue to represent a large reduction of fecal coliform contamination when compared to pre-Harbour Cleanup data, which has allowed the watercourse to slowly recover and improve its overall water quality. The improvements seen in the Marsh Creek watershed demonstrate that the efforts and costs behind Harbour Cleanup established a pioneering example of how a community can improve the management of urban waterways to enhance aquatic habitats and the health of its citizens.