A City Engineer's Viewpoint on River Management

Based on a speech given by Hugh Quintilio,
City Engineer
City of Calgary
October 14, 1994

City engineers make decisions about drinking water, stormwater and sewage treatment

The City of Calgary manages three major types of water treatment - drinking water, stormwater run-off and sewage treatment.

Reservoir Water Quality

Overall, the drinking water quality in the Glenmore Reservoir has deteriorated as a result of upstream human activity and ranching all along the entire Elbow watershed. In 1989, the city started checking stormwater outfall pipes for solids, nutrients, coliform bacteria, flow rate and heavy metals that may have washed off Calgary streets. This monitoring arose out of concern for the loading of the Glenmore Reservoir with as much as 400 kg of phosphates each year.

Updated Treatment Plant

The updated Glenmore Water Treatment Plant is state of the art but has resulted in utility rate increases for everyone. Chemical waste (alum sludges) from the plant is no longer dumped into the Elbow River because it suffocated fish spawning beds. Even our filter cleaning backwash water is now reprocessed to remove chlorine because the Elbow River is an important spawning tributary for brown trout.

Replacing leaky pipes is a first step in water conservation

Leaky Pipes

Some twenty-five years ago, a large amount of drinking water was lost through pipe leakage - as high as 27%. Through extensive pipe replacement costing hundreds of millions of dollars, leakage has been reduced by 10%. The result is a delay in the need to build new water treatment facilities.

Water Meters

Water conservation is an important measure to keep costs down and reduce the impact on the river. Calgary is installing "pay for use" water meters in all new homes and free of charge in existing homes if the homeowners wish.

Stormwater

Urban stormwater from street run-off is the second largest contributor of contaminants to the Bow River. Stormwater contains nutrients (phosphorus and nitrogen from lawn fertilizers), trace metals from automobiles, bacteria from dog feces, pesticides, sand, dust and illegally dumped chemicals.

Stormwater retention ponds are used to protect streams by capturing urban run-off. While they are a drowning hazard to children, they do hold water back in a form of treatment and do prevent flooding. The settlement of flood silt over several days in retention ponds increases water quality.

Heavy metals and oil products from street run-off contaminate rivers

In 1978, the city built the first large-scale 20 hectare 50 acre stormwater retention pond at 68 Street. The University of Calgary is now looking into the benefits of artificial wetlands and "natural" cleansing. Federal money will be directed to the construction of our first such artificial wetland for treating Calgary's storm water.

We have two labs for researching and monitoring stormwater. In addition, we can capture and divert the first flush of snowmelt and all its grossly polluted water into retention ponds. We have numbered all outflow pipes and have posted emergency phone numbers on them. In the future, we're looking at automated monitoring.

Land developers are building dry ponds - depressions on playgrounds and schoolyards. After a major storm, water is held for several days out on the fields. However, there are drawbacks as the fields are not playable 100% of the time, silt clean up is costly and sub-drains will be required below the fields in the future.

Trout Unlimited Canada has a program to paint a yellow fish symbol next to storm drains in an effort to raise public awareness that the drain is a direct link to the river. The Yellow Fish Storm Drain Program also informs people of Toxic Round-Up Days every September and engine oil recycling at City Landfills.

Some efforts must also be directed toward educating schools and youth groups who presently and illegally pour soapy water from car washes into storm drains.

Bridge Spills

We are greatly concerned about vehicles using the Glenmore Causeway and are going ahead with expensive measures to control any pollution that may result there. Two emergency phones have been installed and spill response materials have been stored nearby. All new bridges will channel deck drainage into 24-hour retention ponds rather than directly to the river. Retrofitting the six existing bridges would be difficult and extremely expensive.

Landfill Groundwater

A program of groundwater monitoring and test holes is underway at old landfill sites. If leachates are detected, we'll need funding for ground water cut-off walls.

Sewage wastewater is a major source of river pollution

Wastewater Treatment

Sewage wastewater is a major source of river contamination. Approximately 50 municipalities are licensed to discharge sewage directly or indirectly into the Bow River. Calgary's two wastewater treatment plants account for nearly 90% of all wastewater effluents entering the Bow River.

A new ultra-violet (U.V.) disinfection system has reduced wastewater fecal coliform bacteria counts by 99.99%. With U.V. treatment, there are no residual toxic chlorines and no impact on the ozone layer. However, U.V. treatment is at significant added cost. Ours is the largest U.V. system in the world. We also have a system for biologically removing phosphorus and that eliminates the need for alum chemicals.

There are two different end products from city wastewater treatment - wastewater effluent and sludge. The City of Calgary annually recycles 18,000 tonnes of sludge as fertilizer to farmers' fields surrounding the city.

Calgary has upgraded its facilities regularly over the years and now has one of the most effective treatment facilities in Canada. In the last four years, we've had a 6.5% population increase without any effects seen in downstream water quality.

In summary, the City of Calgary Water Treatment Department will continue to protect the Bow River if given the necessary funding to do so.