FLUXOLOGY REPORT 3

Hello friends! I must start this newsletter with an apology. My last correspondence was in February of 1998…. so much for an annual Fluxology Report. But I have good excuses for not keeping up with my newsletters! 1998, 1999, and 2000 went by in a blur. Project work was intense and personal changes kept my head spinning. In May of 1998, my sweetheart Lorrie accepted my marriage proposal and we were wed! I am happy to report over two years of marital bliss. And if you find that she answers the business phone in my absence, that’s because she runs the show around here. Lorrie left her position at CH2M HILL and has been working with me professionally as the office manager-accountant-secretary for over a year now. What a blessing! I can’t tell you how great it is to have help with all the more difficult and arduous components of the business. We have also made some changes to the facility here on the farm. We replaced the old trailer with a new ‘manufactured’ home, built a guest house/office, and appointed the backyard with a Koi pond. Between work and home projects, farm and ranch fun, activities at Church, and water sports at Lake Shasta, life is surprisingly exciting here in Dead Bluff!

Now back to work. There has been a boatload of new and exciting applications for area source assessment in the past three years using the recommended US EPA surface emission isolation flux chamber (flux chamber). The new applications are always fun because they bring new challenges. Different types of clients have brought new projects and project settings that include unique residential, municipal, industrial, and agricultural sites, even military base restoration projects (yeah Pearl Harbor Naval Facility!) A good example of a new and different application is conducting area source testing at gold mine sites. Cyanide extraction processes have many different, low-level area sources (fugitive hydrogen cyanide and ammonia) including slurry tanks, leach pads, and lagoons. My friend, colleague, and boat captain Tom Card with Environmental Management Consulting (1) and I conducted assessments at several gold mines in Nevada and Colorado (2-lagoon, 3- slurry tank). The mines are located in wonderfully remote locations and the miners are a kick to work with! Plus they pay in gold ingots (just kidding).

Projects at solid waste facilities have included municipal, industrial, and agricultural facilities. We have closed many burn pit landfills (military bases and municipal sites) without needing caps or gas collection system installation. Flux testing combined with landfill modeling (Ray Kapahi with Air Permitting Specialist) adequately provides for site assessment supporting closure. This shot of the sun coming up over the flux chamber on a burn pit landfill is one of my favorites (4). Cap closure design is also a common application (5- fixed gases, VOCs, HCN), but the most unique landfill application has got to be the Wet Soil Cover System (WSCS) designed and built by those smart engineers at Ciba (6) for their Superfund site in PA. The cap includes an ingenious water saturated soil layer and water barrier collection system designed to contain toxic compound release through a standard soil cap. With bi-annual testing we have demonstrated effectiveness. One of my favorite things about this project is that rainfall can’t cause a delay; the test area is saturated by design!

Municipal wastewater treatment (WWT) projects continue to focus on assessing odor-odorous compounds and our source-assessment approach provides unit source data that helps to direct engineering solutions (7). Most municipal WWTs have strict fenceline odor and odorous compound limits to maintain. On-site sulfur compound speciation of area sources at MDL’s of less than 10 ppbv provided by Dr. Eric Winegar with Applied Measurement Science has added a new dimension to source assessment for engineers like Larry Hentz with PBS&J in solving odor problems at combined WWT/compost facilities. The paper and pulp industry continues to regulate chlorinates and methanol along with odor. Remote testing at large lagoons is always interesting; a combination of rustic beauty in the quiescent zones (8) and heavy action around the large surface aerators (9). VOC emissions from a WWT in the Deep South brought alligators (no joke!) to the flux chamber for a look-see at almost every test location. The smaller ones were bold and curious (10) and, fortunately for us, the larger ones (11) preferred to stare from a distance. Oh the perils of fluxing in the outback! It made me feel like that daffy Crocodile Hunter guy. Actually, I think the local Cajon food at the seafood buffet was more dangerous than the gators!

Industrial land redevelopment is very popular these days and many sites require source assessment to assist in site remediation, permitting, and redevelopment process. These sites typically have residual waste materials and groundwater contamination, and, as a result, need to demonstrate acceptable exposure for the proposed land reuse. The combination of surface flux testing combined with the downhole flux chamber testing remains as an excellent approach for assessing contamination sources and source persistence (12). Sites in industrial areas are typically zoned industrial and higher levels of residual waste and exposure are permitted (13- maximum soil flux potential test). Light industrial or office space over groundwater plumes may involve barrier technologies for use in new construction, especially for office building developments (14, 15, 16). Ever wonder about groundwater well completion? Elevation adjustment at this one site left the groundwater wells slightly exposed (17); not only did it look weird- kind of a Stonehenge thing; it was real difficult to sample the wells!

By far the most significant and controversial area source assessments of late have focused on current and future land use for sites with low-level groundwater contamination. The issue centers around the process of infiltration of volatile contaminants found in soil gas through the soil column and cement slab (18, 19, 20- even basement walls) into a structure. Dozens of structures have been tested for infiltration through slabs using the flux chamber. Indoor infiltration assessment using the flux chamber divorces infiltration sources from other sources of indoor air contaminants (outdoor air, off-gassing of materials, product/solvent use) and typically show no significant exposure via infiltration of soil gas to residents. Testing at several school sites with underlain groundwater plumes or buried soil waste residue has been used to show no significant exposure to the school kids (21). Flux chamber testing on open soil, through cracks in surface covers (asphalt/cement slab), and on soil (excavated) under surface covers have provided accurate exposure data for use in exposure assessment in residential and commercial building sites alike while avoiding the data limitations and costs of indoor air studies. One project at a community center included modeled exposure using groundwater and soil gas data as well as indoor and outdoor flux. Conservative modeling (22- J&E modeling using soil gas data) showed unacceptable risk as compared to measured open soil outdoor flux at the foundation (23) and indoor flux measured through the slab (24) showing acceptable risk. We intend to publish this study. We also hope to include discussions about the process of infiltration including key variables that affect infiltration of soil gas into structures. Note that if you are going to take soil gas in evacuated canisters for this type of assessment, collect the sample without exceeding a significant subsurface vacuum (i.e., <20" water) using an apparatus as shown (needle valve and in-line manometer); this prevents concentration enrichment related to lower pressure at the point of sample collection.

That’s it for now. There are lots and lots of great projects on the horizon. Keep looking for those two new books (Aspects of Air Pollution at Hazardous Waste Sites and Odor Assessment Using the Flux Chamber)! These projects were started but not finished. The conference presentations and publications are still taking precedence over these book projects. Let me know if you can use my help on any projects this year. Also, please let me know if you need any of the publications listed on the web site.

Take care friends!

Still alive and kick'n .... in Dead Bluff.....

Chuck Schmidt