Thursday, 12 July 2012

Pain in the Drain

 This article was written by Heather Hunter and published in the Summer 2012 edition of 'Between the Issues', the Ecology Action Centre's quarterly publication. Thanks for covering this important topic, Heather. The full BTI can be downloaded here.

The last time you were caught in a downpour, jumping over sidewalk rivulets and trying not to get splashed by passing cars, perhaps your thoughts didn’t automatically jump to where does all this water go? What contaminants might be in it?  But stormwater, the rainwater and melted snow that runs off roads, lawns, roofs and other hard surfaces, is an area where some real environmental action is needed. Storm water often contains motor oil, gasoline, sediment, fertilizer and other contaminants which damage natural aquatic habitats.  Without proper stormwater management practices, serious environmental and economic consequences can occur such as erosion and loss of habitat.

Cameron Deacoff, an Environmental Performance Officer with the Halifax Regional Municipality, took some time to explain why we should be giving this issue some major consideration and steps that we can take at individual and municipal levels to improve our storm water management practices.

Why you should care about storm water management
On earth there is a finite amount of water.  Fortunately, water is efficiently conserved through the hydrological cycle – including the processes of evaporation, transpiration, condensation, precipitation, surface runoff & percolation. This natural water cycle is disrupted by human intervention.  In urban landscapes in particular, impervious surfaces such as roofs, roads and parking lots render the land unable to absorb water. Instead, stormwater runs over streets and sidewalks and along the way becomes polluted with oil, garbage, fertilizers, pesticides and other contaminants.  In fact, studies have shown that storm water conveys up to 600 pollutants, many of which may be harmful to both humans and the environment.  Unlike sewage wastewater, stormwater is often not treated before it enters our waterways.

While good stormwater management has always been important, it is now being seen as more of a “hot button” issue as people are gaining a better understanding of the impact on environments, including erosion, removal or destruction of fish and wildlife habitat, and pollution causing direct damage to fish and other aquatic organisms.  We are understanding that stormwater needs to be managed - efforts should be made to reduce contaminants in street run-off, and there should be some treatment before stormwater joins up with natural waterways.  In addition, there is an understanding that we should avoid directing stormwater into wastewater systems (i.e. sewers that handle wastewater from toilets, tubs, laundry etc) because wastewater systems are not designed to treat stormwater flows. During heavy rainfall events, treatment processes can fail as throughput exceeds the capacity of treatment facilities, resulting in untreated overflows. Other risks associated with poor stormwater management include flooding, basement backups, and associated property and financial losses.

The importance of stormwater management is not going to decline any time soon.  Cameron explains that aging infrastructure is making the issue more serious today. “Much of the infrastructure in the ground was put there several decades ago,” he says, “and maintenance and replacement needs are ramping up”. He adds that “climate change is also having an impact on the issue, because our weather patterns are changing, resulting in increasing volumes of precipitation, and increasing intensity of rainfall events. Winters have been milder, resulting in less storage of precipitation as snow and ice, making for shifting hydrological patterns for which stormwater management systems were neither designed nor constructed.”

What you can do
To enhance your individual stormwater management practices, Cameron provided the following tips:
  • Retain as much natural land cover on your property as possible (i.e., do not cover the ground with asphalt, concrete, etc. unless necessary).
  • Disconnect your downspouts (eaves troughs, foundation drains, sump pumps, etc.) from your house onto the surface of your property for drainage into the ground; or at least ensure that they are not connected to the wastewater sewer system.
  • Store and manage waste materials properly so that they do not flow into storm sewers, swales, etc., during a storm. This includes covering dirt piles, removing litter and pet waste.
  • Landscape your property with plants and other materials that are native to where you live. These have fewer needs for fertilizers and pesticides, which should be used sparingly if at all.
  • Support fees for storm water management. These services benefit you and the environment.

At a municipal policy level, there are many steps that cities and towns in NS can be taking to improve stormwater management practices.  Some recommendations include:
  • Having your town or city conduct a review of water-related issues within their jurisdictions, and those shared with neighbouring municipalities.
  • Ensuring that municipal urban design & planning jointly consider water quality and water quantity along with land use and transportation.
  • Devote some attention to retrofitting issues in older urban areas, not all towards improving development practices in new "greenfield" areas.
Some municipalities such as the City of Cambridge in Massachusetts and Victoria BC have begun implementing progressive by-laws to counter stormwater pollution.  In Cambridge, significant investments in catch basin cleaning, street sweeping, and urban forestry programs have been made.   

In Victoria, bylaws have been passed for businesses as well as construction and development sites. Businesses must be fitted with a “Storm Water Rehabilitation Unit”, which is a generic term for any system designed to remove targeted contaminants. In general, any system that removes solids such as gravel, sand and silt, and floating materials like oils and trash should be adequate. At construction sites, regulations prevent construction waste water from being directly joined to drainage systems or sewer systems, hazardous wastes are tightly controlled with spill plans in place, and after construction has finished the site must be cleaned up to prevent excess gravel, dirt and pollutants from entering natural waterways.

Stormwater management practices may vary across municipalities, and depending on existing infrastructure, different levels of investment may be required. However, the first step is to raise our level of awareness about this issue.   To reduce harm to our natural waterways, and our overall ecological footprint, stormwater management must become a permanent part of our “environmental consciousness”.

1 comment:

  1. I never imagined that stormwater are serious threat to our environment! People should be aware of it and the government should provide stormwater management program for their community.