← Back to the list of projects

City of Ann Arbor SSWWEP - Citizens Advisory Committee Coordination — City of Ann Arbor

← Back to messages

2.14 -P- What are the current and planned normal and peak capacities?

Posted by Lori Byron on 20 Dec, 2013
Category: Category 2 - about potential recommendations

Frank Burdick’s Log Number: N/A
Submitted by: August CAC meeting
Category (1,2,3): 2
Status: Closed
Estimated date to address: N/A

Q. What are the current and planned normal and peak capacities?

A. The current present day average flow into the treatment plant is 19.2 mgd. The projected need in 2025 is 24.3 mgd. The annual average daily design capacity of the City’s current wastewater treatment facility is 29.5 mgd.

Comments

Joe Conen on 14 Jan, 2014:

The daily average flows are informative of overall plant capacity relative to normal demand.
As a followup, I am still interested in the peak flow handling capability of the treatment plant to understand storm related issues. I would like to understand this in relation to the peak volumes (demand) experienced during the storms and past treatment plant overflow events. This question relates to Category 2, Development of recommendations.

Lori Byron on 5 Feb, 2014:

[CITY]
The attached excerpt from the WWTP Facilities Master Plan prepared by Black & Veatch in 2003 contains design parameters of the plant. By definition, any sustained flow over one of these design flows could be considered as exceeding the plant’s capacity. However, in these instances the consequences may be insignificant because  the plant is able to contain the flow and treat all wastewater to acceptable discharge standards. In instances when the plant is not able to do so, it is typically because plant flow increases faster than plant operators can react to bring equipment on-line that is not needed at the lower flow rates, which can result in a sanitary sewer overflow event.  As part of the SSWWEP study, we’ll be looking at the peak flows amounts which that plant experienced during recent storm events.

Staff is working on getting the full 2003 WWTP Facilities Master Plan uploaded to Basecamp. (It's an extremely large file.)

Lori Byron on 7 Mar, 2014:

Posting the url to the WWTP Facilities Master Plan, posted on the City's website. The document is also posted here on Basecamp, on another thread. 

http://www.a2gov.org/Documents/2004_WWTP_Facility_Master_Plan_Redacted.pdf