In 4 previous posts and in a series starting August 24 I reported on several hazardous waste programs in Missouri. These programs concern abandoned mine lands, superfund sites (both the NPL and Missouri Registry sites), brownfield sites, and underground storage tanks sites. This post summarizes the findings of those posts.

It seems that abandoned mine lands may represent more acres of hazardous land than any other type in Missouri, some 22,149 acres in total. The number has grown each time I have looked. The hazards represented by these lands only sometimes involve contamination with toxic chemicals. They can also include dangerous structures or walls, or open shafts into which one can fall.

The sites listed by the Superfund Program are among the most dangerous of Missouri’s hazardous waste sites. The worst and most dangerous of them are listed on the National Priorities List. Missouri has 33 such sites. Other site that don’t rise to the level of danger of those on the National Priorities List are listed in the Missouri Registry Annual Report. Sixty-one sites are included in the Registry, 1 of which is listed Class 1 (immediate threat to public health or the environment, must be remediated immediately), and 12 of which are listed as a significant threat to the environment (action required, but does not have to be immediate). A site is included only if it is contaminated with a substance that meets the federal or state definition of hazardous. Many hazardous substances are not classified as hazardous. Further some sites that are candidates for the Registry are under assessment or under litigation. Thus, there may be contaminated sites that are not included in either the National Priorities List or Registry.

Brownfield sites represent smaller properties. Though the contamination on them may be sufficient to prevent continued use of the property, it is generally not sufficiently large to represent a threat to the general public health. An example would be a site used as a dry cleaning establishment that became contaminated with dry cleaning fluid (trichloroethylene). Sites contaminated with lead paint or asbestos would be other examples. Because they are unusable, they tend to sit abandoned, forming eyesores and economic drains on the communities in which they are located. Owners are not required to register brownfield properties. Rather, there is a voluntary program for owners who want to remediate their property to state standards and receive a letter certifying the cleanup, enabling the properties to be sold and redeveloped. In total, 1,102 properties are participating in this program or have done so. Some 633 of them were assessed as having no reason to suspect environmental contamination, while the remaining 469 underwent further testing/cleanup. The sites are widely scattered across the state, but tend to concentrate in cities.

Underground storage tank sites (UST) may represent the most numerous individual sites across the state. These are (were) almost all used for storage of petroleum products (for example, the storage tanks buried under the pumps at your local gas station). Operators are required to register them with the state, build them to certain standards, and operate equipment designed to detect if a leak occurs. There are currently 3,332 operating UST sites in Missouri, 10,139 that have been closed, and 1,512 other petroleum sites. It is difficult to tell from the database maintained by the Missouri Department of Natural Resources exactly how many of these have leaked in the past, but data on currently operating sites suggest that about 41% of them may have. If that percentage applies to the total number of sites, it would mean that 6,143 of them have leaked. If a UST leaks or is closed, the owner is required to clean the site, and most have received a No Further Action Letter from the Department of Natural Resources. Only those properties closed after 2004, however, could receive a letter with restrictions indicating that some environmental concern remains. Some 9,254 sites received a letter prior to 2004, and what the final status of those site is, I don’t know. Of the total number of sites, only 2,365 are listed either as currently undergoing corrective action or assessment, or as having received a No Further Action Letter with restrictions. If the department had issued letters with restrictions prior to 2004, however, I believe that the number of sites with a No Further Action Letter with restrictions would be higher.

Thus, Missouri is home to tens of thousands of sites that are, or potentially could be, hazardous due to contamination with hazardous materials. Many of these sites are small, representing a hazard on the site itself, but not to the public generally. Whether such small sites exist in sufficient numbers to represent an aggregate threat to general public health is not addressed in any of the sources I have consulted. How might such a threat occur? For example, thousands of underground tanks might each leak a little bit. Individually it would not amount to much, but together it might be enough to get into local groundwater supplies. It’s just a hypothetical, but we see such effects occurring with the runoff of farm chemicals. The databases don’t address it.

It is difficult to gather overall information about all of the hazardous waste sites in Missouri because the sites are administered by different programs and listed in different databases. The criteria for inclusion differ between programs, and I have not yet located a governmental resource that attempts to summarize all sites in one large overview. The database used to generate the E-START mapping utility seems to be the most comprehensive. In addition to mapping the sites, the utility allows users to download the database. I could not find, however, any documentation specifying the content. It may exist, but I couldn’t find it.

Mostly, the databases do not seem oriented toward providing high-level overviews of trends in the numbers over time, which is the focus of this blog. The data seem aimed at providing the public the location of specific sites, descriptions of the contamination at each site, and descriptions of remediation efforts. For these purposes, it is amazing how much information is only a click away, especially for sites in the NPL or Missouri Registry. If you are interested in information regarding specific sites, then I urge you to consult the resources listed at the bottom of each of the previous 4 blog posts, you may be able to find what you are looking for.