3rd International Symposium on Shallow Flows

The 3rd International Symposium on Shallow Flows will be held at the Iowa Institute of Hydraulic Research at the University of Iowa June 4-16 2012. 

A special session honoring the life and work of the late Professor Gerhard H. Jirka will include a paper on Site Scale Remote Sensing of Mixing Zones.

Offshore Oil and Gas - NPDES Draft General Permit

USPEA issued the NPDES 2012 Draft General Permit recently. 

The permit is for discharges from the offshore subcategory of the Oil and Gas Extraction Point Source Category for the Western Portion of the Outer Continental Shelf of the Gulf of Mexico (GMG290000) .

The draft permit is available in PDF format at 

http://www.epa.gov/region6/water/npdes/genpermit/index.htm

The permit requires the use of CORMIX to model worst case critical dilution concentration (CDC) conditions for produced water discharges from offshore oil and gas drilling operations.

CorPlot - sediment bottom deposition contours
from a simulation study of drilling muds and cuttings discharge

CORMIX can model and predict the fate and effects of produced water discharges from offshore oil and gas drilling operations. The model can provide water column suspended sediment and tracer concentrations in addition to dimensions of the resultant disposal plume.

Additionally, CORMIX can be used to model drill cuttings and muds discharges from offshore operations. 

The model can be used to model bottom sediment deposition over time varying ambient current conditions.  

 

Marine Outfalls

Here is a nice non-technical Wikipedia entry for Marine Outfalls - 

http://en.wikipedia.org/wiki/Marine_outfall

Schematic diagram of a harbor outfall  system

Of course outfalls can also discharge into rivers, lakes, and estuaries, however this a good summation about general characterisitcs and issues associated with wastewater disposal.

-RLD

Mixing Zones

Regulatory Mixing Zone

A regulatory mixing zone is defined as an "allocated impact zone" where numeric water quality criteria may be exceeded as long as acutely toxic conditions are prevented.


A regulatory mixing zone can be thought of as a limited area or volume where the initial dilution of a discharge occurs.


Water quality criteria apply at the boundary of the (regulatory) mixing zone, not within the mixing zone itself.