The Contaminant Loadings Report: A True Measure of Hamilton Harbour’s Success
BY Julie Vanden Byllaardt
ON March 7, 2019
Have you ever wondered what flows into Hamilton Harbour?
You’re not alone. I am asked this question all the time and at the Hamilton Harbour Remedial Action Plan Office, it is our responsibility to know and share this information.
However, to answer the question we need to travel way back in time… about 100 years.
Back to a time when you didn’t need to sample contaminants to know they were in the water. Oil slicks floated to the surface periodically and brown turbid waters lurked throughout, as the coastal inlets of the Harbour were slowly infilled to make space for industry and port activities. Raw sewage was dumped into the Harbour when wastewater treatment technologies were non-existent.
Over a century’s worth of pollution was visible to the naked eye.
Historical photograph of what once used to be the murky waters of Hamilton Harbour contrasted with the blue waters known today.
At one point the Harbour was so off-putting, that a fence was installed in Hamilton to prevent human contact with the water. This was the pinnacle of Harbour pollution – the pre-1970s. A picture often forgotten by the younger generations.
Despite the intensity and length of time the Harbour received contaminants, the Hamilton Harbour story is going to have a happy ending because contaminants aren’t visual anymore, we can only measure them.
Great strides towards restoring the Harbour were made when laws came into effect in the 1970s (e.g., Municipal Industrial Strategy for Abatement) restricting the levels of contaminants entering waterbodies. Since the 1980s, the Remedial Action Plan has worked with many partners to set even more stringent targets to limit contaminant release to the water.
Periodically the Remedial Action Plan gathers partner data and summarizes the total known amount of contaminants entering the Harbour in a report called the “Contaminant Loadings and Concentrations to Hamilton Harbour”, in shorter form known as the Loadings Report. It estimates the amount of a contaminant per day, or “loadings”, entering the Harbour going all the way back to the 1990s. See the full report here
This document is important because it demonstrates just how far we have come in reducing contaminants to the Harbour. For example, this figure below shows the reduction in phosphorus flowing to the Harbour. Phosphorus is a naturally occurring element needed to sustain most life forms including humans (meat, dairy, and nuts are rich in phosphorus). However, when there’s too much in the water we call it a ‘contaminant’ because it has negative effects including instigating algal blooms, like the spectacular bloom Hamilton Harbour had this past summer.
release of phosphorus to Hamilton Harbour per year. HHRAP 2018.
Importantly, the report has evolved through time as measurement techniques became more sophisticated and opportunities to measure more sources became available. Steel mills and wastewater treatment plants are not the only places contaminants could come from. There are also underground holding tanks called combined sewer overflows (CSOs) that sometimes have to overflow to the Harbour during big storms to prevent backflow of storm water and sewage mixtures into Hamiltonians’ basements. At this point in time, even contaminants from the rivers and creeks can be estimated and tracked.
The report also highlights the sources with the largest impact on the restoration of the Harbour, which is helpful to decision makers. The Woodward Wastewater Treatment Plant has historically been one of the Harbour’s largest contributor of contaminants, but tertiary upgrades will be completed in a couple of years. Once the switch is flipped to tertiary treatment, for the first time in 100 years, the quality of water coming into the Harbour will be determined by the watershed – the next largest contributor.
Despite great strides to reduce contaminant loadings to the Harbour, there is still more to do. Many projects are underway, like the cross-connection program and real-time control of CSOs, but some are still in the planning phases like the Dundas Wastewater Treatment Plant upgrades. Low Impact Development projects, such as the creation of bioswales, are starting to gain speed in Burlington and Hamilton – these are important because they “catch” contaminants from road runoff before entering storm sewers and/or creeks leading to the Harbour.
The Loadings Report is important because it serves as a critical
reminder of what the Harbour would be like if investments towards better
water quality were not made. The next iteration of the report will be
after the Woodward upgrades are complete – and will be one tool that
measures the success of a truly paramount investment in the water
quality of the Harbour.
Bioswale created in the Brighton Beach community in Aldershot. Rainwater
from the street collects in the bioswale and is naturally filtered by
the ground before reaching Hamilton Harbour.