This post is a continuation of a theme I first began exploring in two previous posts, “The Chicken That Laid Leaden Eggs, and Other Horror Stories,” and “Brownfield Remediation For Urban Homesteaders.” What I discussed in those earlier posts was the problem of soil pollution in urban environments, and the impact of that pollution on efforts to practice safe and sustainable urban farming and urban food gardening.
As noted in those earlier posts, there are many individuals, volunteer groups, nonprofit organizations, research bodies and governments who are tackling the problem of remediation of urban environments in order to foster safe urban food production. Their efforts are vital in helping localities build local food systems so that they can stop relying on industrial factory farming and long, fossil fuel-dependent supply lines stretching from centralized farms to local supermarkets. This last week I had the privilege and opportunity to speak with a member of our own city government, who is involved in the issue of brownfield reclamation. Mr. Clark Henry is an urban planner who serves in the City of Portland Brownfield Program, and he agreed to be interviewed for this blog.
We discussed the extent of urban pollution in the United States, the various kinds of urban soil contaminants, and the costs of some brownfield remediation strategies, as well as the uncertainties associated with these strategies. Following is a transcript of our interview. My questions are in bold type. (I did something different for this interview: I captured it on a digital recorder. I was thinking of making it into a podcast, but in listening to the interview, I wasn't quite satisfied with its pacing (this is my fault, not Mr. Henry's), and I'm not sure I like hearing my own voice...so I chickened out. Maybe next time.) The interview is rather long, so I am breaking it up into two posts. Next week I will post Part Two, God willing.
People talk about adapting to Peak Oil, economic collapse and resource constraints...and there are all sorts of responses, including trying to make things work where we live. Food systems are a big part of this, including urban gardening and urban farming. But some have pointed out the pollution of the urban environment, including pollution of soil due to lead. Telling people, “Don't grow food in the city; it's too dangerous,” won't fly as people find that they can't afford to rely on our present food systems. Yet the issue of pollution is valid. Can you comment on the scope of the problem, starting with lead pollution?
Sure, and just to qualify my statements, I am not a scientist, but an urban planner. I've been working with this [Portland Brownfield Program] project for eight years, so I have developed some understanding of levels and pervasiveness of contaminants. My wife, however, is director of the Josiah Hill III Clinic, a community-based nonprofit organization that does blood lead level testing for pregnant women and children in lower income neighborhoods and among communities of color.
The #1 source of lead contamination in Portland is lead paint, from older construction and older houses. The problem of lead contamination grows more severe as one moves eastward across the United States and as one goes into older neighborhoods. Scraping and sanding paint, or chipping and flaking of paint is the source of soil contamination in the home environment. In commercial and industrial areas, shipbuilding and shipbreaking, bulk oil terminals, old gas stations and old storage sites for leaded gasoline are sources of lead contamination.
Lead is a background element in nature, and agencies like the EPA and HUD publish environmental lead level figures that, in their view, “do not pose a driving risk to human life.” However, they also say that there is no safe level of lead in the human body. And there are documented detrimental effects to small children up to the age of 7 from exposure to lead. The City and County Health Departments partner with the State to publish guidelines for lead exposure, and there is a “Lead Hotline” available to City residents.
What other contaminants are a concern (including organic contaminants like organic compounds from leaking underground tanks)?
Petroleum of all varieties – gasoline, heating oil, motor oil, diesel fuel, bulk oil, and so forth. Former gas stations occupy a large portion of America's commercial corridors, and they were usually situated on corners where people drive by. Many sites of these former stations show few or no signs of such previous use; yet when people look into the records for such sites, they discover that, “Oh, a gas station was here!”
Modern gas stations operate under rigorous oversight by state regulators, but these older sites represent a mystery, an unquantifiable risk, and available databases don't do justice to this risk. Verifiable sites are maintained in two State (Oregon) Department of Environmental Quality (DEQ) databases: the Leaky Underground Storage Tanks (LUSTS) database, and the Environmental Cleanup Site Inventory. Some of the sites on this list have been cleaned up and re-used. All of these sites are candidates for State involvement in assessment and/or clean-up.
There are two stages of State environmental assessment. First is the Phase 1 assessment in which a consultant determines the history of the site, using sources such as the County library, building records, the Polk Directories and the Sanborn Fire Insurance maps. (In the 1950's, the Sanborn Fire Insurance company made very detailed maps of underground tanks for underwriting purposes.) Also, the consultant will visit the site to do a visual inspection, where he may notice old concrete pump islands or old gas station structures or fill ports for underground tanks.
The Phase 2 assessment follows once the consultant has determined that a site is a former gas station or dry cleaners' facility or metal plating facility or so forth. Phase 2 consists of taking soil samples or groundwater samples, or taking samples of the contents of barrels if there are barrels on the site, or taking samples of the materials of any existing buildings or structures on the site.
Once the assessment is finished, the level and type of contamination is compared to the desired future use of the site. The DEQ is concerned with limiting exposure to contaminants. Thus, a site that meets regulatory approval isn't necessarily cleaned up, but is configured in a way that limits exposure – via placing a parking lot or building foundation on top of contaminated soil so that people are prevented from coming in contact with the bare soil. This is called an engineering control. Another form of control, called an institutional control, consists of placing restrictions on the title and permitted uses of the site.
So then, it is possible that there are sites that would be under institutional controls that forbid their use for urban agriculture?
Absolutely. Unless you worked through a new way of getting the site cleaned up. And the City is working with some groups who are researching how to make brownfields both safe and functional for urban agriculture, whether it's small-scale community gardens or something larger. We're working with a group called Groundwork Portland, which is just a year and a few months old. It's part of a network called Groundwork USA, whose mission is to identify brownfields within environmental justice communities, and to have them assessed and cleaned up and re-used in a way that reflects the surrounding community. Not necessarily to eyeball these sites for condominium development or Starbucks, but to make sure that they are doing something for the people who live there – by protecting their health first, and then by insuring that these sites are used in a way that meets the needs of the people around them.
Groundwork Portland has a board of directors whose members come from several local organizations: Organizing People, Activating Leaders (OPAL); the Oregon Tradeswomen; and the Oregon Sustainable Agriculture Land Trust (OSALT). The Oregon Tradeswomen provide training in hazardous waste handling for brownfield work. OSALT owns property for agricultural use and they are doing research on appropriate agricultural development of urban properties. There is a project on 8th and Emerson in NE Portland, the “Emerson Garden Project,” now being undertaken by OSALT, and it is a 4000 square foot lot that was donated by the County through foreclosure.
The Portland Brownfield Program tested the lot and found that there were really high lead levels in a couple of spots. We (Groundwork Portland, OSALT and the City) are now trying to clean up the soil using phytoremediation (decontamination via plants), in order to turn this lot into a community garden. OSALT will test native plants on this lot, to determine their phytoremedial qualities with lead, in order that we can turn this into a site for food production and education at the same time.
What are the available remediation strategies, starting from the most expensive strategies down to those that are within reach of communities and non-profits?
That's a good question, and the answer is not obvious. Soil removal is one option. But this is very expensive compared to trucking dirt to a regular landfill. Dirt at regular landfills is simply used as a cover. But contaminated dirt requires removal to a toxic waste landfill. Fortunately, there is such a landfill in eastern Oregon, but the cost of trucking dirt there is over $700 a ton, compared to $70 a ton for removal to a regular landfill. And a ton of dirt is not that bulky. So soil removal quickly becomes very expensive, not to mention the cost of finding virgin, clean dirt and trucking it in to your urban agriculture site.
Another strategy is groundwater treatment, but this is an ongoing process that may last several years, and it too is expensive. When dealing with petroleum products, oxygenation and breakdown of compounds using bacteria and/or mushrooms is sometimes used. But this requires continual monitoring. The big questions for bioremediation, and indeed for all remediation, are “How long will this take?”, “How much will this cost?”, and “Who will pay for this?” These are often unknown until one gets into a project. Those who undertake such projects therefore take on a significant risk. Private developers must take this risk on themselves, but communities and tax-exempt non-profits can get help via Federal grants.
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That concludes Part 1 of the interview. Stay tuned for Part 2, where we continue to discuss the costs of remediation strategies. There will also be a debrief and discussion of key points at the end. Meanwhile, here are links to some of the organizations mentioned so far: