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User:Nsr10/Arcata marsh Current Performance

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Opening Comment[edit]

This page is intended to be a hub and portal to updates and analysis of the Arcata Water Treatment Plant lawsuit. It is intended for anyone interested in the subject. Anyone may add data, summit analysis or provide insight to the issues; however, please keep in mind the concept of limited resources. The hope here is to build a community information resource and to clarify the issue. Incomplete information or ideas need to get stated on occation, so they can be discussed, corrected and developed. The goal is a solution or settlement that satisfies the California Regional Water Quality Control Board and the community of Arcata achieved in a timely manner.


Abstract[edit]

Acrata Waste Water Treatment Plant is facing charges for discharging effluent into the enhancement wetlands with high Total Suspended Solids levels over the legal limit. However the violations are a consequence of storm events, failing infrastructure, and the discharge permit interpetations [[1]][[2]]. Furthermore it has been stated that the violations are not harming the bay Arcata marsh Health [[3]].

Flow and Process of the Arcata Wastewater Treatment Plant[edit]

Flow Process diagram r.jpg

The attached diagram shows how wastewater enters the plant, is discharged to the enhancement wetlands and then to the bay. It is important to realize that as wastewater is processed through the plant; it is discharge to the wetlands multiple times. All wastewater pass through the enhancement wetlands at least once; however, when the effluent from the enhancement wetlands returns to the chlorination tank becoming ready for discharge to the bay some of it is redirected back into the enhancement wetlands to dilute the concentration of TSS coming from the secondary treatment. Rethink: How does increase Q affect this processIt is worth considering that the wetlands have two roles. One as part of the treatment processes and the other as nature. How is the health of the wetlands to be decided?

Mass Balance[edit]

The concepts of mass balance are fundamental in understanding the charges as well as the protest to the charges. The mass balance diagrams illustrate how annual precipitation patterns effect the flow rate of the wastewater passing through the treatment facility. The basic jist of it is: Mass calculated by the flow rate (Q) in millions of gallons per day (MG/day) times the C Concentration (C) measured in milligrams per liter (mg/l)

Mass balance diagram for the Arcata Wastewater Treatment Plant in the dry session
Mass balance diagram for the Arcata Wastewater Treatment Plant in the wet session
Mass balance diagram for the Arcata Wastewater Treatment Plant in the wet session with daily rainfall
  • Average: => Q = 2.3 MG/day










  • Wet Seassion: => Q = 5.9 MG/day
  • improve city's infrastructure








  • 80 acres of surface area
  • @ 1 (inch/day) of rain => 2 (MG/day) of water is added to the system









  • All violations correlated to rain events (questionable find evidence of this or remove statement)


Flow Distribution Diagrams[edit]

An ideal flow distribution
An illustration of short-circuiting

An ideal condition









How it is






Intakes an filters[edit]

a[edit]

  • more outlets

b[edit]

  • disk gismo

Definitions[edit]

  • Effluent

Links[edit]

You can put links here using *s for bullets.

Things to be cited[edit]

  • pictures by Dustin Poppendieck

The Issues[edit]

This page illustrates how


1) what are TSS total suspended solids and what are there role in the waste water treatment process. Why is the the city of Arcata violating the TSS limits for discharge?


2) Is Arcata in the Wrong? This page will use the July 30, 2007 California Regional Water Quality Control Board North Coast Region Administrative Civil Liability Complaint No. R1-2007-0064 as evidence. It may not be the treatment plant but the city's infrastructure that needs to be improved.

Things to address are the validity of the problem and the efforts to correct it.

SEE: artical 3


3) Is the marsh part of the treatment plant? The underlining question facing the California Regional Water Quality Control Board and the community of Arcata is whether or not the marsh is legally considered part of the wastewater treatment plant or not. All the violations in the lawsuit are for effluent discharges into the marsh, which is considered by Arcata to be part of the wastewater treatment process, but not so by the California Regional Water Quality Control Board.

The Arcata wastewater treatment plant is a self-reporting agency. It accuracy and validity of the data being reported is not what is in question. So what is the concern? It is the effluent that is being discharged into the marsh. So this section is intended to explain what is being measured namely total suspended solids (TSS), Coliform, Copper, and Cyanide. The flow of discharge charge is also taken into account.


  • 1949-start of a wastewater treatment plant
  • 1957-addition of oxidation ponds
  • 1966 –addition of chlorination
  • 1972-the clean water act

*The time line that is needed is the one of the development of the enhancement or integrated wetland treatment concept. *Discussions over whether the marsh was considered part of the treatment process would be very helpful.

  • 1986-wetland wastewater treatment plant

[[9]]