Starkweather Creek and Lake Monona: summarizes surface testing downstream of Truax.

Truax Stormwater: Storm sewer sampling. PFAS leaking into the storm sewers in the most heavily contaminated area around building 430 (fire station) is split between two outfalls, one of which is on the opposite side of the airport.

Proposed Actions: video inspection of storm sewers (May 2021) followed by repairs intended to reduce groundwater infiltration (scheduled for 2022)

Analysis of the BAM Stormwater Filter: engineering critique of BAM system design, referencing relevant webinars

BAM: from Orin Technologies website

Starkweather Creek and Lake Monona
During the summer of 2019 DNR sampled potential hotspots in several rivers, including the Peshtigo, Menominee, Mississippi, Wisconsin as well as Starkweather Creek and two creeks near Ft McCoy. Starkweather Creek was worst by about two orders of magnitude.

On 10/25/2019 DNR sampled foam and surface water at the mouth of Starkweather Creek
PFAS Sampling Results of Starkweather Creek Due to Foam Sightings
The surface water layer was 400 ppt, about three times the standard water sample at the same location. Foam was 80,000 to 92,000 ppt.

Starkweather Creek drains the area around the Truax/Dane County Regional Airport (DCRA). The surface water & stormwater data from the site investigations is split between two BRRTS pages on the DNR website.

In 2018 the DNR identified the responsible parties (city, county, Wis Air National Guard) and 'requested' they conduct a site investigation to look for PFAS contamination.

When the DNR's own sampling returned PFAS levels in excess of recommended health levels the request became an order
2019-10-07   Responsible Party (RP) letter sent   download
PDF p. 7 map of locations where Starkweather Creek was sampled by DNR
PDF p. 8 table of results, 270 ppt PFOS at the Fair Oaks bridge
PDF p. 12 DHS recommended fish advisory
At the same time Truax stormwater results were sent to DNR
2019-10-07   Supplemental PFAS Sampling for WPDES Permit# WI 0048747-04-0 Renewal      download
PDF p. 2 is a map of the airport showing the locations of the sampled outfalls
PDF p. 3 is a table of results. Note that the water sampled at outfall 32 had PFOS levels averaging 662 ppt
Compare the above numbers with DNR proposed surface water standard
Truax Stormwater
In October 2019 DNR expanded its sampling of Starkweather Creek both upstream and downstream.

DNR Sampling Shows Elevated Levels of PFAS Contamination in Fish and Surface Water in Starkweather Creek and Lake Monona

In June 2021 the fish advisory was extended to the Rock River. DNR has a GIS map and a PDF map which show where they are actively monitoring for PFAS.

Yahara River fish
        advisory 6/2021

Levels in the west branch of Starkweather Creek are around 250 ppt, dropping to 150 ppt after dilution by the east branch.
PFOS levels in fish range up to 140 ppb
Drainage from Wisconsin Air National Guard (WANG) and the east side of the airport is 3700 ppt
Sediment levels are also high downstream of this ditch.

Starkweather Creek and Lake
        Monona sampling results
Fig 1: 12/2021 site investigation workplan, BRRTS filename 20211223_35_SIWP2.pdf, Fig 10-12

It would be convenient to have a single fish tissue health level for reference, but DNR converts the measured fish tissue level to a 'frequency of eating' value. In this case, DNR recommends no more than one serving of bluegill per week. All other species listed should only be eaten once per month.

***renumber my figures
***cite the BRRTS files containing the results

Truax storm sewer sampling
Fig 2: 12/2021 site investigation workplan, BRRTS filename 20211223_35_SIWP2.pdf, Fig 10-10

At this point it is necessary to gather information from multiple maps in order to get an idea of what's happening.

Starkweather samples near Wi Air Natl Guard
Truax stormwater drainage map near WANG
Wiaconsin Air National Guard

Fig 3: Left image (at bottom) shows the location of sample 10 @ 3700 ppt PFOS. The light blue line runs north, parallel to Pearson St until it jogs to the NNW
PDF p. 3 in DNR Sampling Shows Elevated Levels of PFAS...  my annotations in red

Fig 4: Middle image depicts the same area at roughly the same scale. This Mead & Hunt drainage map shows a thick darker blue line in the same position as the light blue line on the left map.  The NNW segment is adjacent to the area outlined in pink, which on the original map is labeled "outfall 101 drainage area".
PDF p. 2 in Supplemental PFAS Sampling...  my annotations in red

Fig 5: Right image effectively zooms in on the area in the upper sections of the previous two maps in order to make the building numbers legible. The red arrows for buildings 430 and 56 emphasize the change in scale. Note that the NNW tip of the drainage ditch is very close to the "New impervious structure" labeled "18" at the lower edge of this map. Final F-35A EIS, PDF p 215 Fig Wi3.4-3  my annotations in red
original download link is disabled:

The Mead & Hunt drainage map (middle image) shows sewer lines in light blue. Close comparison of this map with the right image shows sewer lines that begin at the NNW tip of area outlined in pink, pass east of bldg 56, turn NE to bldg 1209, continue due north, then turn west toward bldg 430, the current fire station.

The draft site investigation work plan offers a drainage map with a more complete set of boundaries.

Building 430 drainage
Drainage area for outfall 32

Fig 6: Left image zooms in on bldg 430, which appears to be split into two parts by a drainage area boundary
Southern nozzle test area 1 is in the drainage area for outfall 21 leading south to the drainage ditch parallel to Pearson St.
Northern nozzle test area 2 is in the drainage area for outfall 32 (see description below of right image)
p. 11 Fig 2 my annotations in red

Fig 7: Right image shows drainage areas and outfalls for the southern portion of Truax. Note the sewer line just north of bldg 430, running from east to west as indicated by the black arrow heads. It runs under the main runway, past the sample location labeled 032A, and drains into the west branch of Starkweather Creek at outfall 32.
p. 12 fig 3 my annotations in red

At the end of April 2020 DNR received stormwater test results which were much more extensive than the 2019-10-07 results discussed above.
2020-04-28    STORMWATER MONITORING RESULTS    download
            p. 9 PFAS results listed by outfall (outfall 21 had 17,500 ng/l PFOS, outfall 32 had 1,173)
            p. 10 results as a map
            p. 11 mass loading calculations show 4843 mg/day of PFOA+PFOS for outfall 21, 3109 mg/day for outfall 32
            p. 14 proposes use of BAM stormwater treatment at outfall 21, investigation of storm sewers

While outfall 21 (nozzle test area 1) had a higher PFAS concentrations than outfall 32, its flow rate is much lower. Or looking from another angle, outfall 32 made a similar PFAS contribution but it was heavily diluted because this outfall serves a much larger drainage area (illustrated by Fig 11 below).

Treatment tends to be more effective at higher concentrations so outfall 21 is the more attractive target.

We can cross-check the maps and test results shown above against a fourth map showing areas of concern around building 430, which shows the heaviest contamination in the base. Measured PFOS levels in groundwater range from 13.8 ppb (13,800 ppt) to 36.8 ppb (36,800 ppt). There is a lesser hotspot along the fuel spill ditch, but that is nearby.

Building 430 and
        associated nozzle test areas
Fig 8: 02-13-581254 WANG-115TH FIGHTER WING    2019-07-11 Site Investigation Report download    PDF p. 80
Note that the nozzle test areas are mislabeled in this image. The southern area is referred to in the text as Nozzle Test Area 1.

It is possible - but not yet proven - that the vast majority of the surface water contamination is coming from the area around building 430. The fact that building 430 nozzle test contamination is split between two outfalls creates the initial impression that there are two major source areas on opposite sides of the airport.

PDF p. 8 shows the location of the Darwin burn put.
Darwin Road is not marked on the sewer/drainage maps but it crosses International Lane at the point where the latter becomes a divided road. The burn pit is in the NE quadrant of that intersection. The sewer maps don't show how it is drained.

The high levels of contamination in this burn pit could be a contributor to surface water contamination. However, it would presumably drain to the west branch of Starkweather Creek which was sampled at the point labeled "11", where levels were unremarkable. It is possible that the relative lack of impermeable surface in or near the burn pit allows most of the rainwater and contamination to seep into the groundwater. Where it goes from there should be a significant issue for the site investigation.
Proposed Actions
DNR orders responsible parties to submit an interim action plan to the DNR by April 16, 2021.
They also comment on the BAM stormwater treatment system:
DNR understands, however, that there are logistical problems with implementing the treatment media in the outfall structure and thus the treatment process has not proven to be successful in reducing PFAS concentrations from leaving the outfall and entering the surface water.
2021-04-16 Response to January 21.2021 Letter Site Investigation Work Plan for BRRTS Activity #02-13-584369 and #02-13-584472 download  PDF p. 11
The Airport will work with a contractor to televise the storm sewer sections identified in Figure 2. These sewer sections were selected based on elevated PFAS concentrations in samples collected during the 2020 PFAS sampling. The contractor will provide a video of the storm sewer inspection and report identifying defects observed. This data will be used to identify appropriate storm sewer remediation to reduce the amount of PFAS contaminated groundwater entering the storm sewer system in outfalls 021 and 032.

Storm sewer defects identified in subtask 3.1 will be corrected using a combination of slip lining, spot repairs of broken pipes, grouting pipe joints, and installation of anti-seepage collars. Sediments in the storm sewers to be repaired will be removed. The specific combination restoration techniques will be determined based on the storm sewer televising. Construction documents will be prepared for this work so the Airport can procure this work in accordance with local, state, and federal regulations.

Note: on 11/2/2021 the airport sent a letter to inform the DNR that the sewer work would be delayed until 2022

Michigan EGLE has documented infiltration of contaminated groundwater into storm sewers at Lockhart Chemical, Axalta Coating Systems and
Buick City and both storm and sanitary sewers at Coldwater Road Landfill. The Navy has done similar work at Willow Grove, PA and Whidbey Island, WA.
EPA lined storm and sanitary sewers at an electroplating facility.

EPA lined a storm

02-13-581254 WANG-115TH FIGHTER WING
Approximately 11,104 feet of storm sewer was televised in May 2021. Storm sewers to be televised were selected based on previous PFAS sampling and flow observations. A summary of the observations from the storm sewer televising is presented in Table 2. and the locations of the storm sewers are shown in the attached drawings C-101 to C-105. An additional 527 feet of storm sewer could not be televised due to debris in the storm sewer.

Table 2 (pages 4 & 5) summarizes observations from the inspection. Following are several sewer diagrams showing the area around building 430, with inspected sewers highlighted. This includes a segment connecting manholes marked 21-10 and 21-12. However, there are two segments running from building 430 to manhole 21-12 which are not highlighted and do not appear in Table 2. They are highlighted in red below. Were they not inspected due to the debris noted above?

          inspected near building 430
Fig 9: Sewer lines inspected near building 430, from 20211206_43_Summary_report.pdf  fig C-101
Note that this sewer map is rotated so that north is to right, unlike the one below. My notations in red.

This seems odd given that this sewer lies well within the plume diagram in Fig 10-8 of the Dec 2021 site investigation workplan.

Estimated plume
          near building 430
Fig 10: 12/2021 site investigation workplan, BRRTS filename 20211223_35_SIWP2.pdf, Fig 10-8

Analysis of the BAM Stormwater Filter
The contamination passing through the sampled storm sewers is a known.
Unknowns include:
  1. How much contaminated groundwater is seeping directly into the creek. Note that the DCGM (Dane County Groundwater Model) indicates that this is likely to happen near Truax. On the other hand, the December 2021 site investigation workplan (20211223_35_SIWP2.pdf) p. 52 notes that:

    1885 The presence of organic-rich marshy deposits has particular significance for retention of
    1886 PFAS mass in source areas.

    1915 The shallow depth to groundwater at the Base, presence of marshy deposits, and low
    1916 permeability of underlying glacial deposits are good indicators that vertical migration
    1917 pathways for the plume may be limited. However, historic maps indicate that the marshy
    1918 deposits are absent in potentially downgradient directions.

  2. How much contaminated groundwater is leaking into the storm sewers as they pass through contaminated soil.
  3. How much contamination results from direct contact of the runoff with contaminated soil.
2021.4.16.Response to WDNR 01212021 letter BRRTS 02-13-584369 and 02-13-584472.pdf
The Airport has worked with ORIN Technologies LLC to install BAM booms at Outfall 021 as a pilot study to evaluate removal of PFAS. Bench top tests of the BAM resulted in over 99% removal of the PFOA and PFOS. The results of the field pilot study have been highly variable PFAS removal rates. This variability is likely due to a combination of water bypassing the BAM booms and sediments being disturbed during sampling and repositioning the BAM booms. Typical PFOS removal was reported to be around 18% and typical PFOA removal was reported to be around 4%. This data has been reported to WDNR in a separate email. The Airport intends to maintain and continue to optimize the operation of the BAM booms at outfall 021 to take advantage of incremental benefits afforded by their removal of PFAS, at least until the completion of the interim actions.

About 28 min into the video of his webinar presentation (notes below) John Cuthbertson describes a case study at Selfridge AFB and comments that he "would rather be treating upstream where the concentrations are highest". If indeed the major sources of surface water contamination are the nozzle testing areas adjacent to building 430 (and perhaps the fuel spill ditch), it makes little sense to wait until the water reaches outfalls 21 and 32 where you have to deal with the water from their entire drainage areas. As illustrated in Fig 11 below, the nozzle test areas are a tiny fraction of their respective drainage areas.

        areas for outfalls 21 and 31
Fig 11: 2019-12-06   DRAFT SITE INVESTIGATION WORK PLAN download
p. 11 Fig 2 my annotations in red

While a relatively large vault may seem an inviting place to install a passive system, if there is any way to intercept water upstream before it is heavily diluted it might be well worth it, even if it is necessary to use a pump to divert the water. You still need to handle most of the surges, but the less total water you have to handle, the easier that will be.

Sampling upstream from the outfalls has been limited to major junctions but suggests leakage around building 430 and adjoining buildings to its northeast.

        sewer junction sampling results
Fig 12: Stormwater monitoring results 4/28/2020 BRRTS file 20200428_43_SW_Monitor_Results.pdf, Fig 4

On 7/29/2021 Michigan EGLE (Dept of Environment, Great Lakes and Energy) hosted a training webinar
PFAS in Stormwater: Treatability and Implications of Emerging Water Quality Standards for Stormwater, part of their
Remediation and Risk Management Series

Approximately 40 minutes into the recording Brandon Steets, PE (chemical) of Geosyntec listed several factors to be taken into consideration when designing a stormwater treatment system: Post-presentation question: what is an adequate contact time for an active treatment system?
Answer: it depends on which compound you are trying to remove and how many log reduction you need (me: greater reduction requires increased contact time)

This presentation strongly suggests that the poor performance of the BAM system is baked into the design by:
Contact time is critical since the PFAS needs to diffuse through the water in order to reach the surface of the activated carbon where it is adsorbed.
Regenesis Stormwater Webinar Sep 29, 2021
John Cuthbertson, Associate Vice President and North America Industrial PFAS Lead at AECOM.
21 minutes    - mostly concerned with releases on surface - AFFF is huge
    - stormwater usually released directly to surface waters
22 minutes    - NJ & MI require testing on new NPDES permits
24 min mitigation
    - passive treatment via media barriers, reduce water contact with contaminated soils/sediments, eg, liners, removal of sediment
    - ex-situ treatment
    - groundwater venting to stormwater (also liner??)
26 min    - aquagate/plumestop
    - ex-situ treatment
28 min case study Selfridge AFB
    - EGLE surface water standards exceeded at outfalls - PFOS up to 10 ppm
    - stormwater study identified 4 catch basins contributing 75% of PFAS
    - installed wier/pumping system to extract and treat stormwater
    - pilot system using a combination of carbon and fluorosorb
    - would rather be 'treating upstream' where the concentrations are highest
Orin Technologies
405 Investment Court, Verona, WI 53593

Bioavailable Absorbent Media (BAM)
BAM is the worlds greatest contaminant sponge. It is a carbon-based product made from biomass materials. BAM’s absorption ability or sponge like effect, comes from its unique and diverse honeycomb- structure. The shape creates pores or openings within the structure that allows for contaminants to be drawn in and retained within the pores. This unique ability prevents exterior surface microfilm buildup that allows BAM to continually absorb contaminants.
    Rapid absorption of contaminants.
    Pores provide extremely high surface area per gram of material creating a high Cation Exchange Capacity (CEC).
    Promotes microbial colonization’s that biodegrade contaminants.
    BAM can be combined with chemical oxidants or reductants.
    Effective on a wide range of contaminants.
BAM can be applied by in-situ injection and soil blending. When mixed into solution BAM has a low viscosity that allows it to be delivered through traditional low-pressure methods. Dry material can be directly applied to contaminated soils for simple treatment.

Stormwater pilot test

ORIN conducted a pilot test to treat PFAS impacted surface water flowing through collection vaults using BAM filled booms (8” diameter) and pillows (6” thick). The booms were customized to fit the dimensions of the vault for maximum BAM /surface water contact. BAM booms were placed into the vault and passive flow surface water was in contact with the Booms and Pillow for 27 days before initial inlet / discharge samples were collected for laboratory analysis.

There is no indication of any engineering control over the volume flow rate of water through the booms, suggesting that contact time would be purely a function of the rainfall rate.

April 2021 Plan
This posting also dropped some hints about the upcoming site investigation funded by the National Guard Bureau.
The WI ANG remedial investigation process (RI) will further characterize the contamination in those areas.
The RI will utilize High Resolution Site Characterization (HRSC) technology to investigate the subsurface
heterogeneities for determining exposure pathways, processes affecting PFAS fate, and mass
distribution. The HRSC data will provide essential information to develop a remedial approach and
understand how remedial measures will affect the current state. The Airport will work with other
responsible parties to evaluate whether data from the WI ANG RI process suggests the need for
additional interim actions. If it does, the responsible parties will evaluate an interim action, likely using the
BAM technology based on the ongoing studies discussed in section 3.3 above.