20170806 - Lack of Complete, Central Database Hampers Understanding of Dioxane Plumes

Lack of a complete, central sampling and well log database is an ongoing issue in understanding where the Pall/Gelman dioxane is, how it got there and where it is going.

Here are some of the 2797 sampling records of the 3760 records from the 1995 Gelman database that have been left off the current DEQ database and 2011 Pall database:

Well Location | date | ppb

3401 Ferry St|19860430|127

3401 Ferry St|19860514|nd

3409 Ferry St|19860430|428 *

3409 Ferry St|19871110|700

3409 Ferry St|19880415|1390

3409 Ferry St|19880415|1460

3409 Ferry St|19881214|1600

3409 Ferry St|19890724|2200

3409 Ferry St|19900131|2200

3409 Ferry St|19910123|2900 *

3417 Ferry St|19860428|166

3432 Ferry St|19860430|647 *

3432 Ferry St|19860514|648

3432 Ferry St|19860515|480

3432 Ferry St|19860626|846

3432 Ferry St|19871015|1450

3432 Ferry St|19880415|1430

3432 Ferry St|19880415|2120

3432 Ferry St|19880831|2900

3432 Ferry St|19881214|3400

3432 Ferry St|19890724|3500

3432 Ferry St|19891023|920

3432 Ferry St|19900131|3200

3432 Ferry St|19900618|3900

3432 Ferry St|19900802|3500

3432 Ferry St|19910115|5100

3432 Ferry St|19910822|5700

3432 Ferry St|19920116|5500

3432 Ferry St|19920116|5500

3432 Ferry St|19920723|5300 *

3432 Ferry St|19930305|5700

3445 Ferry St|19860521|nd

3459 Ferry St|19860428|nd *

3459 Ferry St|19860521|nd

3459 Ferry St|19880418|nd

3459 Ferry St|19881208|nd

3459 Ferry St|19881208|nd

3459 Ferry St|19890719|nd

3459 Ferry St|19900130|nd

3459 Ferry St|19900802|nd

3459 Ferry St|19910813|nd *

3459 Ferry St|19930303|nd

3459 Ferry St|19930303|nd

3459 Ferry St|19930824|nd

3463 Ferry St|19860502|nd

These are important since they show a large mass of dioxane in the "pipeline" heading towards the Dupont Circle area and through an area where the shallower D2 aquifer layer connects to the deeper unit E aquifers.

* Pall or its consultant must have access to this data since some of the missing readings do appear on at least one cross section diagram:

Another strange thing about this diagram is that it shows a well log for boring GSI-98-02 with dioxane readings of 8300 ppb, 8410 ppb and 7580 ppb, but these ppb readings are not included on the GSI-98-02 well log that SRSW has nor are they on any well log from DEQ.

This screenshot of a Google Earth mashup of Pall's 2000 plume map & 2001 unit E potentiometric map show a possible path for how the high dioxane levels got to the deeper levels at the Dupont Circle area:

The lack of monitoring wells ahead of the 3000+ ppb plumes on the way to the Dupont Circle area is alarming. Even the recently installed MW-118 seems to miss the 3000+ ppb plume. Subsequent plume maps shift the suspected pathway to Dupont Circle without adequate supporting data.

In 2008, the general flow of the Dupont Circle layer is still to the northeast:

... but the monitoring wells MW-54d & MW-55 intended to monitor the flow through Dupont Circle may be installed about 15 feet too shallow to detect the main flow... perhaps because of an apparent repeated error in 465 Dupont Circle's database elevation as depicted (or omitted) in various cross-section diagrams:

20000608-XsectDupont-BB-465Dupont-Error.png

20020212Exsect-DD-465DupontErrors.png

20070827-PLSDupontWorkPlan-page_7-465DupontError.png

20080410-Dupont-08-07+MW-121d-ver2-465DupontErrors.png

20140206-Evergreen Cross Sections-2014 B-B'+465Dupont.png

20140206-Evergreen Cross Sections-2014 A-A'-MW-121d-fix+465Dupont-ElevErrors.png

Detail:

Dioxane could be slipping to the north or northwest underneath the thin clay layer separating MW54-d from 465 Dupont CIrcle... or it could be moving to the west toward MW-121d, which also may be screened too high to catch the main flow from Dupont Circle.