September in the U.K. is the season for political and academic conferences, with highlights ranging from a speech by Bill Clinton to seminars on siphonic roof drainage and positive air pressure transients.

Issue: 11/02

In the U.K., late September is the political conference season. All three major political parties hold seaside conferences where party delegates from across the country debate with their political leadership the content of the party's platform for the coming year. The parties rotate through Brighton, Bournemouth and Blackpool each year. This year the governing Labour Party held its conference in Blackpool. The conference was notable for a bravura performance by Bill Clinton as the guest international speaker, unaccountably accompanied by Kevin Spacey, who must have found the whole process more confusing than a visit to K-Pax. Both were later to be found in the Blackpool McDonalds, presumably undergoing a reality check. Clinton's speech, where he introduced himself as the representative from the Arkansas CLP (Constituency Labour Party) and received a standing ovation, was excellent and proved once again that there is life beyond the Oval Office.

September is also a favored month for academic conferences, as it represents the last "free" time before students return and our lives are determined by lecture timetables and assessment schedules. I was fortunate to be able to attend two consecutively--the first being the 9th ASCE Urban Drainage meeting in Portland, OR, and the second held the following week in Iasi, Romania, where the Conseil International du Batiment (CIB) held its 28th Water Supply and Drainage for Buildings conference. In Portland, we presented our work on siphonic roof rainwater drainage systems, while in Romania, we presented work on positive air pressure transients and launched the Positive Air Pressure Attenuator (PAPA) on an expectant world.

Portland was an exceptionally well-attended conference, attracting some 400 delegates with a high international content. The work on Sustainable Urban Drainage was fascinating. Papers ranged from the use of swales--grassy infills typically in car parks to reduce the peak inflow to urban combined sewer systems--to the benefits of green roofs. (Green roofs have added vegetation and soil layers that attenuate the runoff to the sewer). It was perhaps disappointing that our paper was the only one on siphonics, as I would have expected such systems, ideally suited to large buildings such as malls, airports and sports arenas, to have been particularly appropriate for the U.S. Previous editions of PM Engineer have introduced the system; however, there seems to be little uptake.

The papers at any conference are the excuse for extended conversations and an exchange of views at evening events. In Portland, the highlight was the reception at the Science Museum. Here some 200 experts in urban drainage "played" with the excellent range of interactive displays, from a wind tunnel to test paper airplanes to water- and compressed air-driven 2-liter water bottle rockets, actually intended for school children. After exhaustive research, it was found possible to reach the ceiling with a 2 to 1 water/compressed air mixture. For readers from Portland, or any visiting, I would recommend an hour or so in the Science Museum.

Portland also gave me the opportunity to visit old friends from Washington, D.C., now settled in Salem; however, it also left me with a Portland-Seattle-Heathrow-Edinburgh-Amsterdam-Bucharest air ticket, over 36 hours, followed by a seemingly interminable bus trip to Iasi in northern Romania. While the CIB conference was less well-attended, the papers from the U.S., Belgium, Brazil, Japan, Taiwan and Romania were excellent. The concentration was on water conservation, enhanced design methods for water supply and drainage and solid deposition problems from w.c.s or food grinders. My group presented our work on positive air pressure attenuation and introduced the PAPA device. This collapsible, sealed bag within a vented containment cylinder may be connected to a building drainage system to absorb any positive air pressure transients, removing the necessity for an open to atmosphere vent for every vertical stack. The concept and the prototypes on display were well received, and the manufacturer recorded its first orders. As the inventors of this device, we look forward to monitoring its acceptance within our international community. However, I expect that acceptance will take a little while--British understatement perhaps, but a view based on experience.

The acceptance of mechanical devices, even if of the passive and "fit and forget" variety, presents apparent problems of understanding to code bodies internationally. Julius Ballanco's comments in the June edition concerning the acceptance of air admittance valves are a fair summary of the attitudinal difficulties. There is a lack of understanding of the role of AAVs and what they can and cannot do that is not confined to the U.S. Recently a member of the public contacted us because he was experiencing positive pressures in his house drainage network during heavy rain. His builder attributed this to the AAV that terminated his stack not venting the pressures caused by surcharge in the downstream combined sewer. In the U.K., one in five dwellings on a new site must have an open vent. However, removing the AAV does nothing to solve the real problem, and our advice was that he and his neighbors should monitor the situation, as it is likely that the real cause of the problem is poorly designed or installed main drains.

Finally, congratulations to Dale Nieman and Brian Moore, both of whom correctly identified General Douglas MacArthur as having said, "These proceedings are closed," at the signing of the Japanese surrender in 1945. Two bottles of wine await collection in the university's extensive wine cellar next time Dale or Brian passes through Edinburgh!