Junction Construction: Predicted Greenhouse Gases and Air Pollution

Below, we print the recent public comment to City Council by resident Paul Chrostowski, PhD, QEP, on the greenhouse gas emissions from construction of the proposed Junction development plan. We also print a companion piece he posted yesterday on the air pollution impacts.

TAKOMA PARK CITY COUNCIL Public Comment

MAY 27, 2018

Environmental impacts of major construction are often overlooked, with a focus on the finished product rather than the construction process. However, construction can have significant impacts on air and water quality.

For example, the removal and disposal of the existing asphalt/concrete parking lot will likely involve jackhammers, compressors, front-end loaders, and roll-off or dump truck haulers. All of these operations use diesel fuel which emits greenhouse gases, sulfur oxides, nitrogen oxides, and fine particulate. In addition, particulate matter from the asphalt and concrete itself will be emitted. At typical published rates of activity, this could mean about two weeks of constant air pollution and noise. As many as 40 loads would be required to transport this material.

During my 6 years on the Committee on the Environment, I pressed for environmental impact analysis of proposed major construction in the City. Since this has not been done, I have undertaken my own evaluation starting with a Limited Life Cycle Analysis of the proposed NDC development plan, focusing on greenhouse gas emissions that contribute to climate change.

I based my analysis on material on the City’s website including the development plan: demolition and removal of the existing parking lot, 50,000 sq. ft. building with one level underground parking, about 8,000 sq. ft. of paving, and no recycling of demolition materials (none required in RFP or agreements). This did not include demolition of Takoma Auto Clinic (Johnny’s) structure, excavation for underground parking, or any street reconfiguration (all of which will also have impacts).

Using standard methods in the environmental engineering profession, I predict that this activity will release about 88,000 MTCO2e (190 million pounds). This is more than the Brendle Group 2013 report predicted for 2018 for the entirety of all greenhouse gas emissions in Takoma Park and would negate all the improvements we have made over the last several years. One would have to plant over one million trees to offset this effect. In reality, we would not be able to mitigate this impact. An alternative design concept I have seen is for a 34,000 sq. ft. building with no underground parking. This would cut the greenhouse gas emissions by about 60% and with careful attention to construction practices and offsets could be mitigated.

I encourage Council to pay close attention to these environmental impacts and engage any developer in a discussion to mitigate the impacts. The legacy of this project should not be that it contributed in any way to climate change or local air pollution.

 

AIR POLLUTION IMPACTS OF PROPOSED JUNCTION DEVELOPMENT

July 6, 2018

In my testimony of May 27, I presented the results of a technical analysis of greenhouse gases (GHG) during construction of the proposed development. At that time, I did not include emissions from the excavation for the underground parking level or impacts from demolition of the Takoma Auto Clinic. Including these, the GHG emissions will approach 90,000 MTCO2e (about 200 million pounds). These GHGs will contribute to climate change and stay in the atmosphere for some 39 years – long after a decision on this project has been made. These emissions are so high that they cannot be mitigated unless the project is made smaller.

In the meantime, I performed an air pollution analysis of diesel exhaust that will be emitted during the excavation for the underground parking. To do this, I focused on air pollutants regulated under the federal Clean Air Act – nitrogen oxides, hydrocarbons, carbon monoxide, and particulate matter. In addition to these pollutants, diesel exhaust also contains hundreds of other pollutants that have been associated with human health effects. I used standard engineering assumptions that the underground garage would be 10 feet tall with a 2-foot subbase resulting in a 12-foot deep excavation. After subtracting 1 foot for asphalt removal and using the dimensions from NDC’s diagrams, this results in a 14,400 cubic yard excavation. We don’t know NDC’s excavation plans, so I developed a benchmark scenario using one 200 HP dozer, a track loader, and 30 cubic yard dump trucks. It would take about 6 months to excavate this hole using this equipment. Using more (or larger) equipment would shorten this time but increase diesel exhaust emissions.

I obtained emission data from the Environmental Protection Agency and the scientific literature. I then used a simple air quality model to project these emissions out to 350 feet from the center of the proposed project, where people are likely to be exposed. At this distance, the diesel particulate concentrations would exceed EPA’s screening level that is based on pulmonary inflammation and the National Ambient Air Quality Standard for oxides of nitrogen. Besides pulmonary inflammation, exposure to diesel exhaust has also been associated with cancer, cardiovascular disease, central nervous system effects and developmental effects according to the EPA and the World Health Organization. In addition to local health effects, this excavation would add about 250 MT of pollutants to the airshed.

Exceeding screening levels in a preliminary environmental impact analysis does not necessarily mean that there will be health effects, but it does mean that there should be an in-depth refined study prior to implementation of construction. This would be based on NDC’s exact construction plans and would include appropriate mitigation measures. It is premature to approve the development plan without considering its potential impact on the health of Takoma Park residents.