Case Study: Stockton and Houston Ship Channels

Case Study: Stockton and Houston Ship Channels Peter Schlosser, April 22, 2008 EESC W4886 Spring 2008 1

Transient Tracers • Tracers: trace substances of natural or anthropogenic origin (stable and radioactive isotopes; chemical compounds. Sometimes toxic or otherwise harmful (contaminants) • Transient tracers: ‘Dyes’ with known delivery rates to the environment (e.g., 3H, 3He, CFCs, 129I, SF6, 85Kr) • Radioactive clocks (e.g., 14C,39Ar) • Special sources (e.g., 18O, Ba, nutrients, Ra isotopes, Rn isotopes) • Deliberately released tracers (e.g., SF6, 3He) EESC W4886 Spring 2008 2

Outline • Motivation • Methodology (quick reminder) • Case Study no. 1: Stockton Ship Channel • Case Study no. 2: Houston Shippihg Channel • Conclusions

Motivation • Important part of urban environment: e.g., public heath, economy • Threatened by human activities occurring on local (pollution), regional (water management, climate), and global scales (sea – level rise).

Objectives • Understand advection and mixing • Study air/water gas exchange • Understand connection between shipping channels and adjacent water bodies • Examine role of tributaries

Methodology: Dye Experiments Conventional dye experiments USGS-Colorado River 2,200 pounds of Rhodamine WT! Portland State University Lower Bull Run River

New ‘Dyes’: SF6 and 3He

SF6: Early Experiments Past: Discrete sampling: low resolution

New Technology Near real – time observation capability established in 2001 (Ho et al., 2002)

Technology: Gas extraction • Hydrophobic polypropylene membrane with pore size of 0.05 µm • Breakthrough pressure exceeding 150 psig so water will not pass through but liquids and gases can be brought into direct contact. • In the case of a gas transfer to or from a liquid, the liquid flows around the outside of the fiber while a gas and/or a vacuum is introduced inside the hollow fiber. Near real – time observation capability: Continuous gas extraction

Tracer Injection

Stockton Ship Channel Schmieder, Ho, Schlosser, Clark, Schladow, Submitted

SDWSC: Motivation • California Department of Water Resources Environmental Checklist • San Joaquin River Deep Water Ship Channel • Demonstration Dissolved Oxygen Aeration Facility • Draft Initial Study/Mitigated Negative Declaration • Reduce oxygen demand by decreasing nutrient loading • associated with upstream water uses. • Evaluate and mitigate the effects of channel deepening within • the DWSC. • Enhance DO levels within the DWSC with the use of mechanical • or non-mechanical aeration techniques. http://baydeltaoffice.water.ca.gov/announcement/IS-MNDPublicDraft020905Release.pdf

SDWSC: DO Injection http://baydeltaoffice.water.ca.gov/announcement/IS-MNDPublicDraft020905Release.pdf

SDWSC: DO injection http://baydeltaoffice.water.ca.gov/announcement/IS-MNDPublicDraft020905Release.pdf

SDWSC: DO monitoring http://baydeltaoffice.water.ca.gov/sdb/af/monitorlocation.cfm

Stockton Ship Channel Schmieder, Ho, Schlosser, Clark, Schladow, Submitted The Basin Plan water quality objectives for DO are 6.0 mg/l in the San Joaquin River (between Turner Cut and Stockton, 1 September through 30 November) and 5.0 mg/l the remainder of the year.

Houston Ship Channel Schmieder, Schmalz, Ho, Aikman, Schlosser

Houston Ship Channel http://www.swg.usace.army.mil/items/hgnc/#MAP

Houston Ship Channel Schmieder, Schmalz, Ho, Aikman, Schlosser

Summary • SF6 has many advantages over conventional dye in studies of surface waters • SF6 experiments allow visualization of water flow and mixing • Stockton Deep Water Ship Channel study shows slow advective water movement and long residence times resulting in low DO concentrations. • Houston Ship Channel study also shows long mean residence times with related accumulation of contaminants released into the channel

Case Study: Stockton and Houston Ship Channels