The third Use Case for SAWGraph aims to support more advanced research questions for PFAS researchers. It involves connecting observations to known or suspected sources and answering questions like:
This use case will receive a stronger focus in Year 3 of the Proto-OKN project, however SAWGraph already supports some basic queries that would apply to this use case as demonstrated below.
PFAS Reasearcher from EPA, state agency or academia
Given a known source of PFAS release or a suspected source based on the facility type, SAWGraph can leverage hydrological features to trace downsream of the contamination. This example traces downstream of Converted Paper Manufacturing Facilities, to examine the pattern in downstream samples of fish and water.
This query begins by locating all Converted Paper Manufacturing Facilities from the FIO graph based on the NAICS code (naics:NAICS-IndustryGroup-3222).
Next it gets hyf:HY_FlowPath (stream reaches) that are in the same S2 Cell as the Facilities using the Hydrology graph. From the stream reaches, it finds connected downstream reaches by following the hyf:downstreamWaterbody links in the Hydrology graph
The last step is to find samples that are in the same S2 Cells as the downstream reaches, and get all the sample properties including the test results for each chemical for the sample types of interest.
In Maine only one of the river systems that is downstream from Converted Paper Manufacturing Facilities has had repeated testing of surface water and fish tissue samples. The Kennebec River does demonstrate high PFAS levels that diminish as you move downstream, however it is worth noting that Converted Paper Manufacturing is only one of the sources of PFAS that have contributed to this river system. Nevertheless this type of query demonstrates how researchers could test new hypotheses based on suspected sources of PFAS contamination, and existing test results.
A further demonstration and code for this query is available here