City Council Candidates Changing Positions on Measure R
On Nishi 2.0: A simple question about fair housing in Davis

Seven FAQs about Nishi Air Quality

Nishi-pic1. What is the Nishi project?

Measure J/R gives Davis citizens the right to vote on whether residences (aimed at students, but not exclusively for students) should be built on the Nishi property.  Two years ago, Davis citizens voted down a project at Nishi.  That project had a commercial component and a residential component.  The new project proposal, often called Nishi 2.0, just has a residential component, plus allowances for daycare, nursery, outdoor exercise areas, etc.

2. Nishi is near a freeway. So what? A number of places in Davis are near freeways.  Do they have bad air quality too?

Studies show that all sites near freeways suffer from poor air quality.  Quoting a recent LA Times article:

When choosing a home, school or day care, aim for locations as far from the freeway as possible.

Avoid sites within 500 feet — where California air quality regulators warn against building — or even 1,000 feet. That’s where traffic pollution is generally highest, along with rates of asthma, cancer, heart attacks, strokes, reduced lung function, pre-term births and a growing list of other health problems.

3. Ok, but if we built at those other near-freeways sites, why shouldn’t we build at Nishi? Is Nishi any worse than these other sites?

Aside from “two wrongs don’t make a right” (that is, we should not repeat the mistakes of the past), there is reason to think that Nishi might be particularly bad. Nishi is adjacent to where I-80 narrows from 6 lanes to 3.  As a result, there is often stop-and-go traffic near Nishi, especially toward the end of the week with Tahoe traffic: 

Typical winter Thursday 
Typical winter Friday

The constant braking releases ultrafine heavy metal particulate matter into the air.  These are thought to be particularly harmful to human health, in addition to other other pollutants that are released. 

So yes, Nishi is likely to be worse than other freeway-adjacent sites.

Plus Nishi is also exposed to pollutants from the railroad - Nishi is sandwiched between the freeway and the railroad.

4. But that sounds pretty hypothetical. How would we know that Nishi is actually worse?

The Environmental Impact Report (EIR) for Nishi relies on a study done by David Barnes in 2015 – February 3, 6:20 PM to February 13, 9:20 PM.

The data show that the PM 2.5 measurements (PM stands for “particular matter”) at Olive Dr are consistently higher than measured by UC Davis & generally higher than measured by Yolo-Solano Air Quality Management District (YSAQMD).

Moreover, Barnes stated that a “peak in ultra-fine [0.09 to 0.0 μm]  elements extends from Friday afternoon to late Saturday. This is the time most likely to be affected by weekend traffic. This is the only time during the study the site was exposed to the weekend traffic and it shows up clearly as the largest concentrations in the ultra-fine signal” (Barnes 2015, p. 9).

5. So, is the air quality issue of Nishi settled, then?

Not quite.  There are at least two limitations to these data:

  • Measurements were only taken for 10 days, so it is unclear how representative those days would be of days throughout the year.
  • Measurements were taken at an adjacent site on Olive Drive, not at Nishi itself; thus, the measurements were not taken adjacent to where the freeway is elevated and to where the freeway narrows from 6 lanes to 3, causing frequent braking.

Also, we’re missing measurements of the worst case scenario: we have no measurements of days when there is bad air quality in the region and there is weekend (Tahoe) traffic.

We need additional testing at the Nishi site itself – as unanimously recommended by the Natural Resources Commission – and for longer than 10 days.

6. So, why haven’t additional studies been done?

Before the last vote on Nishi 2.0, over three years ago, Dr. Thomas Cahill, a professor of physics at UC Davis and founder of the DELTA Group (Detection and Evaluation of Long-range Transport of Aerosols), recommended that additional air quality studies at the Nishi site be done.  He estimated that these studies would cost only $30,000, a small amount compared to the developers’ overall expenditures.  Yet the developers of Nishi chose not to do additional studies, and the City Council did not press them to.

7. What about mitigation? I heard something about trees and air filters?

First, it’s worth noting that the City’s own EIR for Nishi concludes that even with mitigation, the exposure to ultrafine particles and diesel particulate matter at Nishi could potentially be associated with a substantial increase in health risks – and for that reason, the EIR concludes that the impact is significant and unavoidable.

Second, the claims about mitigation make a number of problematic assumptions - for one, they do not take into account that residents would keep their windows open and spend time outdoors.  And there is no provision for warning residents about air quality risks.

Third, any talk of mitigation is premature until we know what level of particulate matter we are mitigating for – which is why we need additional studies.



The reader can draw their own conclusions, but I have argued in an op-ed for the Davis Enterprise that Nishi 2.0 is an environmental injusticeI urge you to vote No on Nishi (assigned as Measure J for the June election).



What about the air pollution from students who have to drive to Davis because they can’t afford to live here? All locations have costs.

[personal attack removed by post author, per comment policy].

Roberta L. Millstein

People deserve and expect a minimum level of safety in their homes. This is recognized in a variety of governmental ordinances. Nishi, as far as we know (again, more testing should be done) does not meet that level of safety. Again, the City's own EIR said that the health impacts would be significant and unavoidable.

Luckily for us, Nishi is not the only place where students can live. We should be insisting that the university provide more housing for students, where they can be housed more safely and without needing to commute. We should not be sacrificing student health in the name of a housing crisis.

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