evaluation of stormwater remediation options on mcvicar creek, thunder bay, ontario / by kestrel wraggett
abstract
stormwater discharge has been shown to impair aquatic ecosystems through the
transportation of nitrogen, nitrate, ammonium, phosphorus, orthophosphate, organic carbon,
fecal coli form bacteria, biochemical oxygen, metals and grease and oil from urban environments
(mallin et al., 2009). stormwater is generally considered a non-point source of pollution which
can cause difficulty in managing habitat and ecosystem degradation. current municipal
stormwater management is often focused on the deployment of end of pipe solutions in the form
of detention or retention basins (roy et al, 2008). there is however a growing recognition that
the public needs to be involved and aware of urban drainage planning ifwe are to move away
from strictly engineered solutions and shift to integrated stormwater management (rauch et al.,
2005).
in 2002, the lakehead region conservation authority (lrca) recognized that mcvicar
creek, one of thunder bay’s major tributaries to lake superior, was potentially contributing
significant sources of stormwater related pollutants to the thunder bay area of concern. the
lower reaches of the creek are highly developed putting the water system at high risk of
excessive urban runoff causing ecosystem impairments.
this thesis is aimed at providing stormwater remediation recommendations along mcvicar
creek through quantitative and qualitative research techniques. mcvicar creek was the selected
location due to the urbanized environment surrounding the creek and the initial recognition from
the lrca. three representative sites were selected that best characterized stormwater impacts
along the creek. the sites were chosen based on previous research completed on the creek by
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and the northshore remedial action plans (rap). ofthe three sites
selected, one site was further studied as a case study site in order to complete a multi-decision
making workshop with stakeholders. all three sites had in-depth subwatershed catchment
assessments and water quality data. in addition, soil texture and composition, soil nutrients, soil
organic matter, infiltration rates and upstream and downstream water quality were examined.
these parameters were evaluated to determine the efficacy of low impact development (lid)
best management practices on the site.
in relation to the literature, the quantitative data show the case study site is a suitable
option for lid remediation. the areas within the case study site that have less than ideal lid soil
conditions could be altered through engineering practices and designs to achieve successful
implementation. the water quality results show excess amounts of ammonia, nitrate, nitrite
phosphate and chloride exceeding specified guidelines outlined by the provincial and federal
governments. the stakeholder group concludes that a watershed-wide education and outreach
campaign is a more valued stormwater remediation option in thunder bay.