This morning, Council member Mike O’Brien announced that he is introducing a bill that would prohibit the installation of natural gas piping systems in new buildings starting July 1, 2020.

O’Brien explained in a press conference this morning that this bill is a follow-up action to the Green New Deal resolution passed by the Council last month, in which the Council committed to Seattle becoming an entirely climate-pollution-free city by 2030. Two cities in California, Berkeley and San Luis Obispo, have led the way in passing legislation to limit further natural-gas installations.
Here’s what the bill does:
- It prohibits natural gas piping systems from being installed in new buildings, including both residential and commercial buildings, as of July 1, 2020.
- It allows the Director of the Seattle Department of Construction and Inspections (SDCI) to provide waivers for up to one year for certain circumstances, such as gas-fired commercial cooking equipment, but only if “suitable electric appliances that meet performance standards are unavailable.” SDCI may renew the waivers annually “should circumstances warrant.”
- It requests SDCI to recommend changes to the city’s building codes to limit expansion of gas piping when an addition is built on an existing building, substantial renovations where existing gas-powered systems are removed and replaced with new gas-powered systems, and extensions to existing gas piping in existing buildings. The recommendations would be due to the Council by July 1, 2020; there is no timeframe in the bill for the Council to review or consider adopting them.
Backed up by representatives from several activist organizations, O’Brien noted that as the public has learned more about the hazards of natural gas as it is supplied today, he believes it is clear that Seattle needs to move away from it quickly and replace it with all-electric solutions for heating and cooking. Methane gas is 25 times more potent as a greenhouse gas than carbon dioxide, and the nation’s pipeline system for transporting it is known to leak tremendously — in fact, according to 350 Seattle’s Jess Wallach, because of escaped methane, natural gas is a worse pollutant than coal. Also, today most of the gas supplied to Seattle is produced through fracking, which has well-documented health and safety hazards from the communities where the fracking occurs. O’Brien and Max Savishinsky of Washington Physicians for Social Responsibility also noted that a recent study showed gas cooktops can create unacceptably high levels of pollutants inside homes (see my notes on the study at the end of this article — its findings have been exaggerated).
As of this morning, O’Brien had not yet discussed his bill with representatives from Puget Sound Energy, the utility that supplies natural gas to Seattle homes and businesses, but he said that he had a meeting scheduled with them for tomorrow. While recognizing that gas is a major line of business for PSE, “the science is very clear,” O’Brien said. “My hope is they realize that they need to get out of this business.”
O’Brien was very bullish on 100% electric homes, touting heat pumps and induction cooktops as the appliances of the future. He shared statistics from the King County Assessor showing that last year 2/3 of new homes in Seattle already had electric heat — though gas heat is far more prevalent in new multi-family and non-residential buildings.
Aaaron Fairchild from Green Canopy Homes talked up the market for all-electric homes, saying that his company has built hundreds of homes in Seattle and Portland with no natural gas. “The market can’t be defined by one appliance,” he said, and describing how much his customers love their induction cooktops which he claims are better, give the cook more control, and boil water faster.
In response to a question as to whether he would be concerned about reducing the diversity of heating and cooking systems in a city known for power outages during winter storms, O’Brien shrugged off the question, saying that Seattle City Light has been working hard on improving the resilience of the city’s power grid, and in the long-term he hoped that community clusters of rooftop solar power would help to alleviate those issues.
When asked whether he thought the future path might extend to banning wood-burning fireplaces and ovens, O’Brien said that he didn’t have an opinion on that, though he believed it would be a move in the wrong direction if removing gas heating systems led to an increase in use of wood-burning fireplaces. 350 Seattle’s Wallach emphasized that natural gas is a substantial portion of the city’s total greenhouse gas emissions, whereas wood burning is not. (O’Brien did admit that he would be sorry to see wood-burning pizza ovens go — “wood fired pizza is SO GOOD”)

When asked about the impact on the restaurant industry and its heavy dependence on gas for cooking, O’Brien said, “Generally we think the technology is already there,” but noted that the legislation provides for waivers and that he was open to a broader exemption to allow new buildings to pipe in gas to areas that were intended for restaurants. He also wants to provide incentives for restaurants to try out what an all-electric kitchen would look like.
In an interview this afternoon, Ethan Stowell, owner of several Seattle restaurants, was skeptical about O’Brien’s bill. “It would get so caught up in legal battles right away, that it’s absurd. Is it going to go anywhere? It seems crazy.” He was particularly negative on the potential for induction cooktops to replace gas in commercial kitchens anytime soon. “They’re not bad, but there’s so much banging around in kitchens, and induction stoves usually have glass tops. The last thing you want is a glass top.” He explained that induction cooktops are already used in his restaurant kitchens, but only for limited uses. “We use them for bringing a pot of water to boil that isn’t going to move all day.”
Overall, Stowell was pessimistic on the restaurant industry moving to all-electric kitchens. “It would be tough. The equipment is a lot more expensive… It would make opening a restaurant hard. The cost of opening a restaurant would go up. The cost of maintaining a restaurant would go up. It would slow down service.” As for the prospects for O’Brien’s bill to move forward, Stowell said, “It seems a reckless but well-intentioned thing that would need to be vetted very well.”
O’Brien’s bill gets its first discussion at his committee hearing tomorrow.
Now back to the research paper cited at this morning’s press conference by O’Brien and Max Savishinsky, the Executive Director of Washington Physicians for Social Responsibility. The study was performed by a team of researchers at Lawrence Berkeley National Labs, in which they built a mathematical model of the level of exposure to three pollutants (carbon monoxide, nitrogen dioxide, and formaldehyde) that are known to be produced by gas-burning cooktops. They then used that model to estimate how often someone would be exposed to pollutant levels above the national and California air-quality standards. This morning, Savishinsky said the study’s found that in California, 60% of homes that cook with gas were found to have pollutant levels at least once a week that would be illegal if found outside.
First, that’s an inaccurate and vastly oversimplified description of the study’s results. The researchers didn’t actually “find” pollutant levels in any homes; they build a model using parameters they gleaned from other research studies. Second, that cherry-picked result assumes that there is no exhaust hood — with an exhaust hood, the pollutant levels and the number of times the standards are exceeded are reduced dramatically. In fact, that is the study’s main conclusion: that it’s very important to use an exhaust system when cooking with gas to avoid exposure to dangerous pollutants.
Then there are the problems with the model itself. It’s very loose: there are several important parameters, including the distance a person is from the cooktop; the level of other indoor and outdoor pollutants that infiltrate the house; how often the ambient air is exchanged in the house; the level to which being indoors concentrates the pollutants based on the number and activity level of the occupants; how quickly nitrogen dioxide settles out of the air onto furniture, walls, and other surfaces; and if there is an exhaust hood, its efficiency in capturing emissions. Most of these parameters are given in ranges, rather than fixed numbers, so in order to generate their model the researchers picked values for some of them, and for others they ran simulations using different combinations of parameters and did a statistical analysis on the result. They didn’t do a real sensitivity analysis on the parameters (they only ran the model 15 times, instead of thousands if they were doing it right and properly exploring all of the parameters), so we have no idea of the true range of possible results or which of those parameters have the most impact on the results. For example: exhaust hoods have a capture efficiency range of 15% to 98%; they used a flat 55% in their model. Did that make a difference, and if so, how much?
And finally, as an article published by Lawrence National Labs on the research team makes clear, electric cookstoves also create pollutant risks. Nitrogen dioxide is produced by any kind of combustion, not just gas burning. Cooking on an electric stovetop also causes combustion, though to a lesser extent than gas. But both gas and electric cooking create something that the researchers claim is even more dangerous than pollutant gases: fine and ultrafine particulate matter that can be inhaled into our lungs and from there move into our bloodstream.
The take-away from the Lawrence research isn’t a clear-cut “gas cooking is super hazardous and must be banned,” as O’Brien and Savishinsky asserted today. All cooking is potentially hazardous. The lesson is that proper, efficient ventilation is critically important to reducing the risks that cooking poses. If you’re not running that exhaust vent when you cook, you’re definitely doing it wrong.
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