Updated June 27 at 10:10 am: The study of noise impacts is now available on the Metrolinx Site. I will review this and other reports in a future post.
Updated June 23 at 9:45 am: The detailed studies of air quality and health impacts are now available on the Metrolinx site. I have not had a chance to read through them yet, and will probably not be commenting on them for a few days.
On June 15, the Toronto Board of Health (an agency that operates independently of City Council but on which some members are Councillors) considered a report from the Medical Officer of Health concerning the impact on air quality of the proposed service expansion in the Weston rail corridor. The recommendations in this report were amended by the Board (see item 24.4 in the decisions of the Board).
The MOH had been asked by both the Board and by the Parks and Environment Committee of Council to review the potential health impacts associated with diesel fumes from the proposed increase in diesel train traffic in the corridor. Noise issues were not addressed by the MOH’s report although they are mentioned in the Metrolinx Part II document for the Environmental Assessment now in progress.
The full Part II document is available online. A much reduced version of the information is available via the consultation portal, but I don’t recommend it.
Many people from communities along the corridor appeared at the Board to make verbal presentations. A common theme in their submissions was that the large increase in diesel traffic in the corridor will have an adverse health impact on those who live, work and go to school nearby, especially children who are more sensitive to pollution effects. In particular, there was a concern that overall air pollution may be contributing to the rising rate of asthma among children, and that the levels expected in the rail corridor, although mostly within “standards” may disproportionately affect families living in the corridor.
Speakers asked that the Board strengthen the recommendations of the MOH which they did by inserting:
The Board of Health … requested Metrolinx to electrify the Georgetown South Service Expansion and the Union-Pearson Rail Link prior to implementing expanded service (Clause 3.a of the decision).
This decision does not bind Metrolinx, but indicates that the BOH considers this to be the preferred way of dealing with the corridor.
One speaker pointed out that the “West Toronto Triangle” is bounded not only by the Weston corridor, but by the Newmarket subdivision (Barrie service) to the east and the CPR North Toronto subdivision (all freight, but with future possible GO service) to the north. Any study of effects in this neighbourhood should take into account the combined effect of trains on all three corridors.
At this point, the MOH has not been able to review the detailed Metrolinx study concerning air quality effects even though the findings of that study are included in the Draft Part II report. This limited the MOH’s ability to assess the underlying assumptions and methodology of the study. The Board has requested that the MOH review this information when it is released by Metrolinx.
I will not attempt to consolidate the large amount of data in the Part II report, but can say that, in general, Metrolinx claims that the projected levels of emissions along the route will be below the levels required by standards except for NOx, and that primarily near Bloor West Station. Because trains will idle here, then accelerate away from the platform, they will produce more emissions than trains simply passing along the line.
The community debate (and by extension the political one) turns not on whether the new GO and ARL services would exceed the maximum allowed by standards, but that any increase over current levels could pose a health risk. The MOH, in answer to a question from Councillor Perks, stated clearly that any increase in emission levels caused by the new services would have a health effect.
The situation is complicated by the fact that there are distinct segments of the line with different service levels. The MOH report (page 6) reproduces Metrolinx information about train numbers. Fully built out based on 2031 projections, the trains per day on various branches will be (current numbers shown in parentheses):
- Via – 12 (6)
- GO Georgetown – 112 (19)
- Airport – 140 (0)
- GO Bolton – 12 (0)
- GO Milton – 97 (12)
- GO Barrie – 87 (8)
- CN Freight – 4 (4)
- CP Freight – 21 (21)
The most densely travelled section of the line is south of Dundas Street through Parkdale and Liberty Village where all services except CP freight share the same corridor.
- Bathurst to Dundas (Barrie service splits off here) – 464
- Dundas to West Toronto – 377
- West Toronto (Milton service splits off, CP freight service enters) to Weston – 301
- Weston (Bolton and CP freight service splits off) to Airport spur – 268
- Airport Spur to Georgetown – 128
The Airport and Georgetown trains account for about 5/6 of the total volume of trains passing through Weston. Of these, about half are the Airport trains which are proposed to be three-car units of refurbished RDCs (Rail Diesel Cars) with new engines to meet modern pollution standards. (Today, there are only 50 trains/day through Weston, and half of these are freights.)
Any projection of emissions must take into account both the variation between types of trains/locomotives as well as the temporal patterns that will vary by time of day. Some of this has been done in the Metrolinx data that are public, but without the detailed background, notably whether the peak period was simulated separately from an all day average. Therefore, it is hard to tell whether the model scenario reflects typical rail operations and variations in concentration of emissions over a typical day’s service.
The detailed discussion of air quality issues is in the Draft EA in section 6.2.4 at page 304 (of the PDF). Metrolinx emphasizes that this is a worst case projection, and actual conditions should be better than their forecast. However, it is unclear whether the 1-hour average projections in table 126.96.36.199-1 represent a peak service configuration, or all day values with emissions spread equally over the day. If the latter, then the projections will understate the actual concentrations during peak periods when service levels, especially on GO, are higher.
Vibration and Noise
Vibration and noise are dealt with in sections 6.2.2 (page 263) and 6.2.3 (page 290) respectively. The MOH did not comment on these sections because the Board’s request to him dealt only with health effects of emissions. However, both of these factors can have health effects by interfering with ordinary life — conversation, concentration on work, relaxation — through the effects of passing train traffic.
Metrolinx proposes various ways to deal with these two problems including floating slab construction (similar to that now used in subway tunnels and theatres) to mechanically isolate the track slab from the surrounding earth, and noise barriers to limit the effects on neighbouring houses.
As with the emission projections, we don’t know whether the model is reporting peak values or all-day averages. Noise standards tend to be based on averages over time on the assumption that both the ambient noise and whatever is added by a new project tend to have ups and downs that are smoothed out over time. This is valid provided that the peak noise levels will actually blend into the background. However, we do know that there will be more trains during peak periods, and the report does not distinguish between all-day values and these peaks. Also, it does not distinguish between periods of the day and week when the ambient levels may be lower and the effect of the new train services may be greater.
The study includes a chart showing relative sound energy vs time values for airport trains (3-car RDC consists), GO trains and CN/CP freights. The freights produce the highest peak because their locomotives tend to be hauling heavy loads, and the longest sustained wheel-on-rail noise due to the length of the trains. However, their numbers are small and there is no projected increase in freight traffic in the corridor. Next down are the GO trains, and the airport trains have quite a small effect both because they are short, and because each car has its own diesel rather than a single locomotive.
Metrolinx proposes to address noise problems with 5-metre high barriers in some locations. This is a “Catch 22” because such barriers also create visual and physical isolation which invite graffiti and crime. They do little good for noise reaching nearby highrises where a line-of-sight barrier is impractical. Neighbourhoods may face the unsavoury choice between a visual eyesore and the noise of passing trains.
The title of this post asks a question, but a definitive answer is hard to provide because:
- The detailed background studies containing the source material for information in the Draft EA are not yet available for review.
- We do not know whether the modelled emissions, vibration and noise presume that all train service is averaged over the day, or if time-of-day effects are taken into account.
- Although most of the modelled emissions lie below standards, each of the emissions is considered in isolation from the other rather than for the potential of their combined increase.
- Electric trains, be they pulled by electric lomotives or as consists of self-propelled cars, are not modelled because this was not part of the terms of reference for the EA. Therefore, we have no basis of comparison with some or all of the corridor services being electrified.
In future posts, I will turn to electrification and to the alignment proposals in the current scheme.