Newsletter - December 2000
ARTICLES OF INTEREST FROM THIS ISSUE
WEAO, WEFTEC and Students
At the opening General Session of WEFTEC in Anaheim, it was announced that WEAO and WEF approved the University of Ottawa Chapter Charter. As the outgoing and first President of this Student Chapter, I was most delighted.
The winner and runner-up of Florida's eighth Student Design Competition demonstrated their designs at WEFTEC. This three-part preliminary design for Loxahatchee River District started with the design of a backbone sewage collection system for a new development in Jupiter, Florida. It also included an expansion of the existing wastewater treatment plant, while accommodating nitrogen reduction to 10 ppm. Finally, the design of a backbone, reuse quality, effluent distribution system for irrigation was required.
The Florida Water Environment Association has agreed to help with the expansion of their design competition to the international level. WEAO has taken up the challenge and our Membership Committee expects to have a team ready for WEFTEC 2002. We are in the process of generating real design problems from private or public companies within driving distances of participating universities and colleges. Any university or college that is interested in incorporating this project into a design course for next year's curriculum can contact Paul Grenfell at: grenfell@daviscontrols.com or Rod Kelly at: rodkelly@videotron.ca.
Teams of four students will compete within an academic design course. The winning team from their academic institution will compete at WEAO's Annual Conference. WEAO's winning team will go to WEFTEC 2002 in Chicago. The projects will be sufficiently intensive so that the brilliance and talents of participating students will be the only constraint to winning at the WEAO Annual Conference and WEFTEC. This program is intended to build bridges between students of environmental disciplines and our profession.
Students and new professionals are invited to take the lid off and participate in WEF and the WEAO. This is your Association. There is nobody else home except for the wonderful people who come before you, your generation and the ones you will mentor.
New programs for new professionals are possible as WEAO continues to develop. An example of one developed by Georgia's Water Pollution Control Association is the EMERGING LEADER AWARD. A new professional with less than five years in the industry is honoured for their outstanding contribution to their Association. I believe a special category for new women in our profession is needed to acknowledge our sisters and daughters contribution to our environmental profession. A second non gender category would also be appropriate. Imagine, that could be you!
Rod Kelly, University of Ottawa, Student Chapter President
Y2K Humbug!
It's December of the Year 2000. Who'da thunk it? Time passes so quickly. It was only a year ago that we were stockpiling food and water, buying generators, topping up our propane supplies, and making plans to spend New Year's Eve at our workplaces to respond instantly should a hidden date-sensitive chip in some obscure piece of equipment malfunction and throw our entire world into oblivion. So maybe you didn't do all those things but they were on your mind, weren't they?
Now the Y2K time bomb is but a distant memory and we worry about how busy the year has been and will the stock market recover soon. How did you mark the millennium year? Did you and your family or your workmates do anything special? Let us know by dropping us a line and we'll publish it in your newsletter. Or you can go into your Association's web site and put a note up in the Discussion Forum.
This year has continued to be a busy and rewarding time for your Communications Committee. As usual, we have published five issues of the Newsletter and continued to improve and update the web site. As we enter a new year, we look forward to more developments: e-mail distribution of news briefs, on-line registration for seminars and the annual conference and more.
But advancements in technology are secondary. As always, the most important factors in putting out a newsletter are the news makers and the news writers. This means you and me! If we want to be treated as esteemed professionals, we need to get our messages and our success stories known within the industry and out in the general public. Keep sending us your articles and help build our profile.
At this time, your Communications Committee, Grant Lee, Sandra Davey, Penny Davey, Emil Cocirla, Lisa Longhouse and I, would like to extend best wishes to you and your families for a safe and joyous holiday season and a happy and prosperous new year.
Peter Takaoka, R.V. Anderson Associates Limited
Precast box culverts used as groynes and aquatic habitat
Precast concrete box culverts do more than channel runoff to provide safe crossings of waterways and drainage systems. They are used as structures for people and migratory animals to pass safely under railways and major roadways. They also serve as storage structures for stormwater to prevent flooding, and tunnels for traffic. Availability, durability, and speed of installation factor, significantly, into the specification of box units.
Culvert installation at Deflector A. Now, precast concrete box culverts have been used as groynes, with a value added ecological feature. This application introduces a 21st century way of thinking to solve a complex problem involving industrial requirements, local tourism/recreation trade, and safe use of waterfront amenities in a major city.
The Dalhousie Yacht Club, founded in 1935, is a well-developed destination on the south shore of Lake Ontario, a few miles west of the Welland Canal. Set in old Port Dalhousie's historic harbour, it has approximately 300 members, with an active fleet of both power and sailboats. In 1988, St. Catharines' Hydro-Electric Commission built the Heywood Generating Station upstream of the yacht club. There were strong current and water surges in the yacht dockage area of the club that raised safety and mooring issues.
Fish habitat material inside culvert units. The yacht club financed a study in 1997, through the Canadian Hydraulic Centre at the National Research Council of Canada, that showed that a series of water deflectors, known as groynes, would redirect currents away from the boat moorings and solve the club's problem with rushing water. A partnership followed between the City of St. Catharines, Dalhousie Yacht Club, and the Hydro-Electric Commission to fund the engineering required to construct the groynes.
When the engineering firm, SHAL Consulting Engineers undertook the pre-design study, it recommended construction of two groynes made with precast concrete box units, after considering rubble mound groynes, and a steel sheet piling deflector that would protrude above the water. The consulting engineer concluded that the rubble mound alternative would cost almost fifty percent more than the other alternatives, and would be unsightly and not conducive to mooring within the yacht club.
The cost of each of the other two alternatives would be essentially the same. Since the box culvert alternative would be more attractive and better suited to being incorporated into the mooring basin, it was recommended as the preferred solution. Construction was scheduled for the spring of 2000, but the challenges were not yet over.
The lands within and around the harbour are federally owned and managed by Small Craft Harbours, and waterfront projects in the area are subject to permission from the federal Department of Fisheries and Oceans. In addition, approval for timing of construction is also required from the Ontario Ministry of Natural Resources (MNR) to avoid the spawning season of certain fish species.
The MNR issued an absolute requirement to complete construction with minimal in-water work by the end of March or first week of April. The Canadian Coast Guard issued a permit that required completion of construction by the second week of April, or another permit application would need to be filed. Approval was also received from the Niagara Peninsula Conservation Authority. The tender for the construction of the groynes called for works to be completed between March 13 and April 30, before the 2000 boating season. This horizon provided enough time to satisfy the constraints placed on the project by various approval agencies.
The precast concrete box culvert option was the preferred solution because:
- It promised little in-water work to avoid disturbing fish habitat;
- It could be constructed quickly within very tight permitting periods;
- It would function fully as a groyne to deflect water flows;
- It could be removed, if necessary;
- It would resist pressures from ice due to its mass; and,
- It would last for the full term of the design life of the project.
But the box units also had another advantage that the designers recognized. Submerged units could serve as fish habitat to enhance the ecology of the fishery in the harbour.
Both groynes were designed to accommodate a two-tier box culvert system at right angles from existing concrete shoreline. Each culvert was comprised of three box units, and each groyne had one culvert placed on top of the other, for a total of six box units.
One groyne, located outside of the mooring basin, was 2400 mm wide x 1800 mm high x 2500 mm long. The second, constructed inside the mooring basin, was 1800 mm wide x 1200 mm high x 2500 mm long. The six units of each groyne had rip rap boulders placed on the bottom for ballast, and the three submerged lower units were filled with loose bundles of pruned tree branches. The end unit of the top culvert on each groyne was capped to prevent the entry of ice and debris. Wooden bumper strips were placed along the sides of each upper unit for mooring watercraft. The end unit of the submerged culvert was not capped, so that small fish could access the habitat of boulders and branches.
Stephens and Rankin staff has years of experience in the Welland Canal and Port Dalhousie area, and knew that the harbour bottom consisted of very soft material, that would not support the weight of the precast concrete box units. SHAL engineers had also considered the bottom material of the basin, and worked with Stephens and Rankin to design rock mattresses to support each of the groynes.
Up to 2.3 metres of 50 mm to100 mm granular material were installed for the mattress of the groyne located at the harbour entrance, and 1.6 metres of the same material was installed for the mooring basin groyne, using an Hitachi 300 excavator. A prefabricated steel channel frame was embedded in the mattresses as a leveling device. A 118 Link Belt and clam bucket was then used to level the upper surface of the mattresses. Divers worked with the machine operator to ensure that the surfaces were level. A rubber strip was glued on the upper surface of each of the lower units before they were lowered onto the mattresses. Then, the upper three units were placed on top of the submerged units. Filler plates on the sides of the upper and lower units locked them together, so that there would be no lateral movement between the upper and lower systems.
To complete the installation, rock was placed around the edge of the units where they made contact with the mattress.
The groynes were installed at a cost of $89,914, plus taxes.
During the summer of 2000, boaters visiting the harbour and members of the yacht club enjoyed safe harbour of their crafts. Anglers were observed catching fish near the publicly accessible groyne located outside of the yacht club's mooring basin. Many members of the club have reported that mooring in the harbour has improved.
Paul Martin, Centennial Concrete Pipe & Products Inc., Cindy Toth, City of St. Catharines, Brian Rankin, Stephens and Rankin Inc.
