Data Being Used to Design Permanent Source-Control System
Today we shared with WDNR and property owners the data from surface water samples taken along Ditch B on December 14 and December 28, 2020 to help inform the location and design of a permanent source-control solution for PFAS.
It is important to note that these samples were taken while the Ditch B Interim Treatment System was undergoing maintenance. Therefore, the system was not operating at full capacity and some water bypassed the treatment system resulting in higher PFAS levels.
The data below includes the regular testing of water quality and PFAS levels approximately 10 feet upstream (SW-L06) and downstream (SW-39) from the interim treatment system in Ditch B and will be collected and posted on a regular basis for as long as conditions allow.
| Location | SW-L06 (upstream) | SW-039 (downstream) | ||
| Compound (ng/L) | PFOA | PFOS | PFOA | PFOS |
| Criteria (ng/L) Date |
420 | 11 | 420 | 11 |
| 10/7/20 | 1,400 D | 300 | 36 | 2.2 |
| 10/21/20 | 630 D | 100 | 130 [130] | 19 [20] |
| 11/4/20 | 2,000 D | 150 | 370 D | 16 |
| 11/20/20 | 2,100 D | 160 | 830 D [740 D] | 51 [53] |
| 12/14/20 | 2,600 D | 160 | 710 D | 41 |
| 12/28/20 | 2,400 | 170 | 670 D [710 D] | 33 [42] |
Notes:
WDNR Permit Criteria = PFOA: 420 ng/L; PFOS: 11ng/L
Detections above applicable criteria are Bold
Duplicate analyses in brackets [ ]
ng/L = nanograms per liter
D = dilution required for sample analysis
PFOA = perfluorooctanoic acid
