a. Process modifications to improve mixed liquor settleability and retain solids
within the aeration tanks and/or clarifiers;
I. Evaluate Nitrogen and Phosphorus Removal Alternatives
1.
“vw fF YN
Perform an initial screening of potential phosphorus and long-term nitrogen
removal alternatives.
Calibrate process model.
Perform computer modeling to evaluate enhanced biological phosphorus removal.
Evaluate chemical phosphorus removal alternatives.
After the nitrogen removal technologies have been screened and identified, perform
computer modeling to evaluate the most viable alternatives.
a. Long-term nitrogen removal alternatives will be primarily focused on
processes that can achieve effluent total nitrogen levels between 6 to 10
mg/l.
b. Considerations will be given to future nitrogen removal processes than can
achieve LOT nitrogen levels. However, process modeling will not be
conducted for those processes as part of this facility plan.
Perform a life-cycle cost analysis of each of the viable phosphorus removal
alternatives identified and evaluate the advantages and disadvantages of each. For
budgetary purposes, assume up to 2 phosphorus removal alternatives will be
evaluated in detail.
Perform a life-cycle cost analysis of each of the viable nitrogen removal alternatives
identified and evaluate the advantages and disadvantages of each. For budgetary
purposes, assume up to 2 nitrogen removal alternatives will be evaluated in detail.
J. Development of Recommended Plan
12/10/19
1.
Review overall upgrade needs and anticipated timing and develop overall
implementation plan addressing:
a. Any phasing of improvements based on either anticipated future discharge
criteria changes or anticipated growth in future flows and loads,
b. Summarizing recommended unit process upgrades,
8 Wright-Pierce
