by Alan E. Pryor, Yolo Clean Air –
Background – In May of this year the Yolo Solano Air Quality Management District (YSAQMD) submitted to the City of Davis a report entitled “YSAQMD Davis Wood Smoke Study_2009-2010” (the “YSAQMD Report” – see Vanguard article, “Hold Your Breath in East Davis during the Winter!” – 6/3/201). This report indicated that air quality tests performed by the California Air Resources Board (CARB) at Slide Hill Park in East Davis from November, 2009 through February, 2010 showed the average PM2.5 concentrations in the measured air were on the order of 100% greater than average PM2.5 concentrations measured at the CARB monitor in the countryside west of Davis. Further, the report indicated that average PM2.5 concentrations taken at Slide Hill Park in East Davis were about 50% greater than average PM2.5 concentrations measured during the same period by CARB in Woodland and Vacaville.
Additionally, information presented in a report submitted to the City of Davis by Dr. Thomas Cahill entitled “Aerosol monitoring in Davis, Winter, 2009-2010” (the “Cahill Report” – see Vanguard article “Cough…Cough! There were Sure a Lot of Wood Smoke Complaints from Davis Residents Last Winter” – 6/4/2010) showed that there were 12 days in which average 24-hour PM2.5 concentrations exceeded the current Federal 24-hour PM2.5 standard at a site in Sacramento identified as “Del Paso”. According to the Cahill Report, the Del Paso site in Sacramento “…is the one that is most likely to have violations of the federal PM2.5 mass standard and thus throw the whole Sacramento, Yolo-Solano, and low elevation regions of Placer and El Dorado Counties into violations of the Clean Air Act.”
Thus, there were approximately 50% greater days in which Federal 24-hour PM2.5 standards were exceeded at Slide Hill Park in East Davis compared to what is otherwise identified by Dr. Cahill as the area with the worst air in the entire region. The Cahill Report also reported numerous complaints of wood smoke by citizens in central and west Davis and concluded there were a number of credible instances in Davis where citizens were adversely affected by what was characterized as “nearest neighbor impacts” of wood smoke. All of these problems occurred after our City Council declined to implement mandatory wood burning restrictions last year and instead relied on the Yolo Solano Air Quality Management District’s voluntary “Don’t’ Light Tonight” (DLT) program. This voluntary program was thus clearly an abject failure.
Additionally, numerous letters to and testimony before the City Council speaks to the widespread nature of the smoke problem in Davis including instances of people taping their doors and windows closed to keep out wood smoke intrusions. One letter and testimony from a new homeowner in Davis reported that she had moved to East Davis with the expectation of cleaner air than in Sacramento and instead ended up making numerous trips to the hospital emergency room in respiratory distress caused by excessive wood smoke in her new East Davis neighborhood.
Yesterday, the Davis Vanguard published an article by this author outlining the legal basis for why Environmental Hazard Disclosures for Wood Smoke should thus be provided to many, if not all, prospective home buyers in Davis based on the prevalence of wood smoke reported throughout the City (see Part I – Legal Basis for Wood Smoke Environmental Hazard Disclosures in Davis Home Sales – 10/27/2010).
Today’s article discusses the estimated impact that implementation of different mandatory wood burning restriction strategies will have on the number of days that are in violation of Federal 24-hour PM 2.5 standards and thus deemed to be “Unhealthy for Sensitive Groups”.
The Impact of Implementing Different Mandatory Wood Burning Restriction Programs on the Estimated No. of Days in Which Federal PM2.5 Air Quality Standards Would Have Been Exceeded in East Davis in 2009-2010
The effect of different mandatory restrictions on East Davis air quality can be estimated based on the experiences of the Sacramento Air Quality Management District that has had a mandatory wood burning restriction program in place for 3-years. The Sacramento Air Quality Management District estimated that their average regional 24-hour PM2.5 air concentration was reduced by 23% on any night in which mandatory wood burning restrictions were implemented in their jurisdiction. This 23% figure is the basis for similarly estimating the reduction in average 24-hour PM2.5 air concentrations that that would have occurred during 2009-10 in East Davis had mandatory restrictions been called based on two different scenarios.
1) Mandatory Wood Burning Restrictions in Davis on those Days in which the Existing YSAQMD “Don’t Light Tonight” (“DLT”) Voluntary Alerts are Called – One suggested regulation was to have mandatory wood burning restrictions in Davis on those days in which the existing YSAQMD “Don’t Light Tonight” (“DLT”) voluntary alerts are called. It has been suggested that this would have substantially reduced the unacceptably high wood smoke concentrations in East Davis on the days in which excessive concentrations are most likely to occur. There were 16 DLT alert days called by the YSAQMD last winter but imposing wood burning restrictions on those days would still have resulted in 13 days in which Federal air quality standards would have been exceeded in east Davis. This would still be the highest number of days in which Federal air quality standards were exceeded by any area in the entire Sacramento region.
This is hardly comforting news to those adversely affected by wood smoke or prospective new home buyers particularly if they have members of their family deemed to be in the groups most susceptible to wood smoke – children, seniors, and those with respiratory impairments. This result also clearly demonstrates the inherent flaws in the manner in which the YSAQMD DLT days are derived. If otherwise there would have been a far more dramatic reduction in average PM2.5 concentrations in East Davis and on the number of days characterized as “Unhealthy for Sensitive Groups”.
2) ) Mandatory Wood Burning Restrictions on those Days as Recommended in the NRC Proposed Program – Another regulatory option would be to have mandatory restrictions based on the recommendations of the Davis Natural Resource Commission which had been submitted to the City Council for consideration but rejected. Imposing restrictions on burning of all wood stoves that produced in excess of 2 g PM2.5/hr on those days on which evening wind speeds were less than 5 mph (approximately 50% of the days during the wood burning season) would have resulted in only 3 days in which Federal air quality standards would have been exceeded in East Davis.
These results are shown in the following table and chart.
Conclusions – Even with a 23% reduction in PM2.5 air concentrations that would be expected to occur if mandatory wood-burning restrictions were imposed on the YSAQMD voluntary DLT alert days during the 2009-2010 wood burning season, the air quality in East Davis would still have had 13 days in excess of Federal standards and would have remained the worst in the entire region.
If mandatory restrictions had otherwise been imposed based on the NRC recommendations and it similarly reduced the PM2.5 air concentration by 23%, only 3 days would have been in excess of federal standards in East Davis during 2009-2010.
This indicates that simply making the current voluntary YSAQMD “Don’t Light Tonight” alerts mandatory will not solve the air quality problem in East Davis. Adoption of the NRC Recommended approach is far more effective in reducing days in which federal air quality standards are exceeded.
Thus, passage of the more stringent NRC-recommended wood burning restrictions would substantially mitigate the wood smoke problem in Davis. Further, informing prospective buyers of residential real estate in Davis of such an implemented ordinance would go a long way towards minimizing the negative impacts of Environmental Hazard Disclosure requirements by demonstrating that the wood smoke problem had been significantly addressed by the City Council.
But don’t hold your breath (unless the air is too smoky to breathe) that the current Council will act so responsibly. The information in this article (Part II) and Part I published yesterday in the Vanguard were all provided to Councilmembers before their latest deliberations on the matter.
What is your rationale for making these assumptions:
1. That Davis is included in the Sacramento PM2.5 non-attainment area because of our fireplace burning rather than because of I-5 traffic and other contributors?
2. That the Sacramento 23% mandatory program success estimate is an appropriate factor on which to base your calculations and conclusions about the Davis situation?
3. That the current Yolo-Solano program has zero impact here and isn’t already reducing Davis’ PM.10 concentrations by 23% or more?
4. That Davis still would have “the highest number of days in which Federal air quality standards were exceeded by any area in the entire Sacramento region” [u]after[/u] making voluntary days mandatory when the Yolo-Solano Air Quality Index now appears significantly better than Sacramento County’s?
5. That the City Council did not already “act responsibly” on this matter, twice? (And, do you really think the council ever would support your contention that every prospective Davis homebuyer be given environmental hazard disclosures because of the minuscule number of “nearest neighbor violators” who’ve been the targets of complaints?)
To: Just Saying – In reponse to your questions above
1. I have not made the determination that Davis in included in the Sacramento non-attainment area. The determination that the entire YSAQMD is in PM2.5 non-compliance by the EPA last year based on their analysis of all sources of PM2.5.
2. I assume we will similar reductions as Sacramento in PM2.5 on no-burn nights because we have similar demographics and almost identical weather conditions.
3. It does not actually matter if the YSAQMD voluntary DLT program has an impact here or not – East Davis air was still the worst in the region so much more needs to be done.
4. I reduced the average 24-hour PM2.5 concentrations in East Davis recorded by CARB by 23% on YSAQMD voluntary DLT days and then noted how many days of the entire 120-day wood burning season still had average 24-hour PM2.5 concentrations greater than 35 ug/m3 (the Federal Standard). It came out to 13 days which was still greater than the Del Paso area of Sacramento (the worst in the region after East Davis) which had only 12 days.
5. The City Council acted irresponsibly by ignoring the abundance and overwhelming body of evidence from experts noting the toxic nature of wood smoke and the very high concentrations of wood smoke in East Davis coupled with widespread complaints from residents – and then did nothing. It does not matter if the City Council supported my contention that Environmental Hazardous Disclosure for prospective home buyers be issued for wood smoke. What matters is if it is a legal requirement by law and it appears to be because of not only nearest neighbor impacts but also because of the extraordinarily high PM2.5 concentrations in East Davis and because people moved here with the expectation of cleaner air. The lawyers and juries will decide if such disclosures should have been made or not.
Thanks for the responses.
1. Sorry I wasn’t clear–I’m wondering about the measurements that resulted in Davis’ determination decision. Was wood-burning’s contribution to overall PM 2.5 levels the same in Davis as in the other Sacramento communities? It seems your conclusions require a certain level of PM2.5 caused by wood-burning in Davis as opposed to the other contributors, such as I-5 running the length of our town.
2. & 3. As you note, there a mandatory program in place in Sacramento County and a voluntary one that covers Davis. I can see why you use 23% for Sacramento’s program (district estimate), but how can you assume that Davis’ program has a 0% success rate? Because Davis is such a nice place–and because there are so few complaints filed here–couldn’t you just as well assume that Davis already has a 25.63% rate? It [u]does[/u] matter whether the voluntary program in Davis has an impact here; don’t your calculations show the number of days change because you assume a rise from 0% to 23%?
4. Are you satisfied that the East Davis CARB measurements are statistically significant and reliable enough to compare the City of Davis directly with the Del Paso site? It seems your conclusions also require this reliability, as well as 23% assumption, and the idea that wood-burning conditions in Davis are the same as Del Paso.
5. The expert expert has very different findings than you. Councilors had to consider this disparity. You and the commission consistently have refused to acknowledge and analyze the record of recent complaints. The councilors had to consider the actual numbers as opposed to your characterization of “widespread complaints from residents.”
You’ve made the argument that the council should pass strong, mandatory restrictions because the “ordinance would go a long way towards minimizing the negative impacts of Environmental Hazard Disclosure requirements.” All I’m suggesting is that the council would have to accept your legal analysis that disclosure is required in order to accept the benefit you’ve described for implementation. Given the council’s poor decisions in the past, how can you think this would carry any weight with them?
Alan,
Thank you for your detailed articles. I have one problem.
You say:
“I am not a lawyer.”
Then you go on to say:
“I have a good understanding of legally required disclosures…
I have a broad knowledge of the legal issues involved….”
And further you make the following assertions and conclusions:
“Thus, as a matter of law any material facts regarding likely exposures to hazardous or toxic substances to home purchasers must be disclosed….
…it would be an undeniable legal requirement to disclose this information…
requires that prospective buyers be properly and explicitly notified … Additionally, they should be advised that….
such seller is explicitly required by law….
the buyer would have standing to bring a lawsuit for damages or reverse the sale of the home…
published an article by this author outlining the legal basis for why Environmental Hazard Disclosures for Wood Smoke should thus be provided…”
You are not a lawyer. Maybe you’d better say that again, because you wrote both articles as though you were one.
Are you really troubled that Alan is proclaiming on matters legal without being a legitimate attorney? He might have extensive legal training without becoming a lawyer. Or he might have have stayed in a Holiday Inn Express Tuesday and Wednesday nights. We have a lot of self-identified legal experts here. Remember, attack the opinion not the person…or whatever.
[quote]Or he might have have stayed in a Holiday Inn Express Tuesday and Wednesday nights.[/quote]
Do they teach law?
justsaying: the simple use of less specific conclusions and more nuanced analysis would be more appropriate, in my opinion, in the absence of professional standing.
To: Just Saying
Re: The 23% reduction is the estimated reduction of avaerage 24-hr PM2.5 air concentrations that the Sacramento AQMD realizes when they call for a mandatory no-burn day. It sounds as if think it the percentage reduction of the number of people who burn on a no burn day. If so, then I obviously did not do a good job explaining myself.
I do not knoow the details of the Sac AQMD study or exactly how they came to this determination or the bsaeline they used but the 23% estimated reduction has been widely touted by them as a measure of the success of their mandatory program in reducing regional PM2.5.
And like Davis now, the Sac AQMD also had a voluntary program for a number of years before they went to mandary restrictions 3 years ago. And they have almost an identical weather conditions and somewhat similar burnining demographics. So I think comparing the estimated reductions between what Sac has seen and what we could acheive in Davis with mandatory restrictions are probably valid. But you are correct in that it is an estimate that has inherent statistical inaccuracies…the true number may be higher or lower.
Re: Confidence of the CARB monitor data – CARB does more PM2.5 monitoring than even the EPA. I looked at the graphs of the daily and hourly data comparing the East Davis CARB monitor data and the Central Davis YSAQMD monitor data and they have a very similar profile in terms of daily fluctuations so I am GUESSING that they would have appromimately the same standard deviations in the data skew…but they are clearly higher across the board in East Davis as shown in the graphs in the report and subsequent article. Neither CARB nor YSAQMD provided a statistical analysis with their data.
Don Shor: “Alan,
Thank you for your detailed articles. I have one problem.
You say:
“I am not a lawyer.”
Then you go on to say:
“I have a good understanding of legally required disclosures…
I have a broad knowledge of the legal issues involved….”
And further you make the following assertions and conclusions:
“Thus, as a matter of law any material facts regarding likely exposures to hazardous or toxic substances to home purchasers must be disclosed….
…it would be an undeniable legal requirement to disclose this information…
requires that prospective buyers be properly and explicitly notified … Additionally, they should be advised that….
such seller is explicitly required by law….
the buyer would have standing to bring a lawsuit for damages or reverse the sale of the home…
published an article by this author outlining the legal basis for why Environmental Hazard Disclosures for Wood Smoke should thus be provided…”
You are not a lawyer. Maybe you’d better say that again, because you wrote both articles as though you were one.”
GOOD POINTS DON…