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2022 Outfall Mapping Ad Hoc Committee White paper for MS4 permit reissuance

Summary: Outfall Mapping ideas, mapping requirements, outfall definition consistency

Please send feedback to:
Maureen Meehan, Pierce County [email protected]
Angela Gallardo, City of Tacoma [email protected]
Concerns/Questions:
Currently tracking size and material, would that be required going forward? (2017 document
says these attributes are optional)
Timeline: As you observe or will special inspections be required to populate material/size for
all outfalls by a given date?
Outfalls digitized from as-builts might not be as precise and field conditions affect precision in
field
possibly different language for outfall in phase 1 permit/WSDOT permit
Why does material matter?
Sometimes difficult to find outfalls based on lat/long
Solutions/Proposed Permit Language:
Continue requirement for all known and accessible outfalls vs timeline to have dataset
complete with size/material
If material/size is required, phase in 2 years after new permit effective date
Use AGO (ArcGIS Online) to share data instead of annual download
Precision based on source of data (digitized vs field collection) and conditions at time of
collection or digitizing
Ecology auto-populate location data (simple Python script)
Potentially add elevation as a recommended (not required field)
Outfall should be defined consistently in all permits.
Filename: Outfall-Mapping-whitepaper-Final.pdf
File Type: pdf
File Size: 89 KB
Author: Ad Hoc Committee