The Pine Ridge sub-division in Guelph, Ontario, is located in the middle of a gravel outwash plain of glacial origin, presenting some unique challenges to the developer.

With no stream in the immediate vicinity to handle storm runoff, rainfall tended to either evaporate, infiltrate or evapotranspire. Since infiltrated groundwater in the area feeds the headwaters of a nearby cold water stream, and at least one municipal well, a stormwater installation would have to both minimize the potential contamination of groundwater and prevent any sediment clogging of the infiltration measures.

After assessing several alternatives, consultant Gamsby and Mannerow Limited recommended the installation of Stormceptor units, based on three factors:

· Efficient performance of the units, confirmed through extensive testing;

· Limited space required (not land-consumptive), due to the Stormceptor system's vertical design; and

· Ease of implementation and installation. The pre-cast concrete construction, employing standard concrete components, enables the units to be used in place of traditional structures.

A total of seven Stormceptor units, strategically located within the Pine Ridge development, were used to protect the 14 hectare (34 1/2 acre) site. Through the entire construction phase of the development ­ when sediment loads in runoff water are typically at their highest ­ the Stormceptor units operated to expectations. The system continues to function extremely well.

For more information, visit Stormceptor's web site at: www.stormceptor.com.

Scientists from Leeds University in the UK, have developed special equipment to discover whether air is self-cleansing and will be still fit to breathe by the millennium.

To collect the data, Dr. Dwayne Heard and his colleagues have been taking readings from air samples collected from Scottish, Yorkshire and Irish shores. Here air carried by the prevailing westerly winds is believed to be purer than that passing over Europe where it gathers pollutants. Dr. Heard is trying to find out if the atmosphere can cleanse itself of trace chemicals, notably in the troposphere. By measuring the oxidising capacity of the atmosphere, it may be possible to determine the tropospheric production and destruction of polluting ozone.

However, measuring reactions between trace compounds and other constituents is complex as the atmosphere is driven by sunlight generating highly reactive, but short-lived intermediates known as radicals. They have low concentrations and a short life-span. Dr. Heard and his team have invented a new technology called Fluorescent Assay by Gas Expansion (FAGE), to take readings of the radicals. Consisting of a mobile laboratory, an air-conditioned box with vacuum pumps and electrical equipment, FAGE searches for the elusive chemicals including the hydroxyl (OH) radical comprising linked oxygen and hydrogen atoms.

FAGE's detection system draws in an air sample which is illuminated by ultraviolet laser. This excites the free radicals into a higher energy state producing a faint fluorescence. FAGE takes a snapshot of this which, when processed by computer, reveals the fingerprint of the hydroxyl radicals. By calibrating their instrument using standard samples, the Leeds scientists can work out how much hydroxyl is present in air. Eventually, it may be possible to discover if the atmosphere is self-cleansing and how it reacts to pollutants.

For further information, E-mail: dwayneh@chem.leeds.ac.uk

The Chesley Lake Lung, is a pioneering effort in lake remediation, by Friends of Chesley Lake, Ontario Ministry of Environment and Energy (MOEE) and my company IPEX Inc., a PVC pipe manufacturer. It has shown a capability to dramatically raise oxygen levels and virtually stop blue-green algae pollution which has traditionally impaired many lakes throughout Ontario.

The Lake Lung supplies pure oxygen to the cold, bottom waters of the lake, through a process known as hypolimnetic aeration, while maintaining the lake's stratification. The oxygen is generated on shore and distributed throughout the lake through the Lake Lung's PVC ducting system. The Lung itself is suspended over the deepest basin of the lake.

The Lake Lung will be installed for the 1997 season in Chesley Lake where water quality problems have been a result of extensive cottage development over the years, resulting in a build-up of organic matter and sediment on the lake bottom. The settling of this decomposing organic material at the bottom, resulted in the depletion of oxygen by early summer. With no available oxygen, the aquatic food chain and fish habitat were severely impacted.

The seriousness of the problem at Chesley Lake was brought to IPEX's attention by Andy Gemza, Inland Lake Specialist with the Environmental Monitoring and Reporting Branch of the MOEE, in a search for the right products to build the Lung. The harsh freeze-thaw conditions faced by the Lake Lung in an open lake setting necessitated the need for a product with structural integrity and longevity.

IPEX recommended Ultra-Rib pipe for flotation pontoons and Vent Ducting for the Lake Lung's body. After five years of testing at lakes in southern Ontario locations, the PVC products emerged with pipe integrity intact.

The proof is the water. Oxygen levels have been revived. Beach closures due to algae pollution have stopped and water clarity has sharply increased. IPEX has donated the lung itself.

If you would like to know more about the Lake Lung program, contact E-mail: vesosob@sympatico.ca.