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Ann Arbor's System is "Tight"

Posted by Michelle Lovasz on 20 Feb, 2014
Category: No category

Cresson informed us that public officials in other communities have told him that Ann Arbor's water system is "tight".  In some other place on Basecamp Frank B has asked after the practice of scoping the pipes in this system for leaks.  I did not actually look at the answer, but I did read Frank's response which seemed to imply that very little scoping had been done within a certain time frame. 
1.  Cresson, on what basis have these public officials in other communities formed their professional approval? 
2.  Is there a norm, a standard, or code (City, County, or State) for how Ann Arbor is responsible for surveying their system? 

I am curious about this line of thought because it feeds into the "if its not broken then don't fix it" standard, which then leads us to the contention of determining to whose idea of "broken" shall we subscribe in our recommendations.

Comments

Robert Czachorski on 20 Feb, 2014:

Michelle - 

I will let Cresson provide the answer on the basis of statements made by other public officials, and the standards used for surveying their system.  Cresson is not in this CAC basecamp, but I will ask Lori to add it to the Q&A log for the City.

One thing that we can do to quantify the "tightness" of the Ann Arbor system is to benchmark it against other sewer systems around the midwest that we have analyzed. We have 70 sub-systems from other cities that we have modeled in our benchmarking files.  This will show how the A2 system performs relative to other systems, and also help rank or prioritize the various districts in A2 that we have modeled. This analysis is in progress and we will share when it is ready.

Take care,
Robert

Frank Burdick on 23 Feb, 2014:

I did not want to imply that very little '"cameral scoping" of pipe had not occurred. What I said was, upon review of the actual repair work that has been done, very little repair work is shown  as being completed in the target neighborhoods.  

Other parts of the city are shown with various pipe repairs and man hole repairs.  This same work  is not shown in the targeted neighborhoods.

A skeptic could conclude that this was intentional.  Ie: so that any flow reductions could be atttibuted to just fdds in those areas and this would justify continuing the program.

Frank Burdick on 23 Feb, 2014:

Regarding the statement: "Cresson is not in this CAC basecamp"...........

Why is he not included on this CAC basecamp?  He is contributing statements to Basecamp and in Public Meetings, CAC Meetings, and Technical Meetings.

He should be reading the many posts on Basecamp.  Perhaps this may speed up the response time from the City, to the questions being presented from this CAC.  Perhaps also, it may improve the coordination with the other ongoing CAC's and Studies.

Robert Czachorski on 23 Feb, 2014:

Very little rehab work was done on the public sewer system in the priority districts because most of the wet weather flows were thought to come from footing drains, based on the 2000 metering and the pilot FDD work done. The flow removal results verified this for most of the district. 

The decision was made to only have Nick on Basecamp from the City as the project manager, and ask Lori to manage the Q&A and disseminate the questions to the City outside of Basecamp.  The City then meets weekly to review the questions, prioritize, and make assignment to get answers. This was done to most efficiently use the resources of the City staff, while addressing all of the questions.  

Frank Burdick on 23 Feb, 2014:

this answer regarding the lack of rehab work is astounding to me.
lets see if i can make an analogy...
so you inherit some old car.   you take the car to the mechanic because there a bunch of fluids leaking from it.  you decide to focus on the oil pan because you suspect that that is the main source.  ytell the mechanic not to worry or even look at the transmission, the power steering, the brake fluid etc...

Is that what the city did in the target areas? Robert are you telling us that the city chose to only look at fdds in the target areas? Astounding and incriminating.

Frank Burdick on 23 Feb, 2014:

regarding the statement, "The decision was made to only have Nick on Basecamp from the City as the project manager,"

Who made this decision? Was it just the consultants or was the city  staff involved?

Why then has there been very very little exchange of info from other ongoing Studies and CACs?

Perhaps, due to the intertwining complexities of all of the issues related the ongoing studies, the city should devote more than one project manager to the process.  

Robert Czachorski on 23 Feb, 2014:

The City and the consultant team made the decision on how to manage the Basecamp process together.  I believe it is working.  Questions are getting answers and a lot of dialog is occurring. A strong team is emerging.  If you believe additional resources are needed from the City, feel free to make your case to them.  In my opinion, it is working quite well.

Frank - in your car analogy, all of the items you listed on the car are mission critical and could each cause failure of the system.  It is not a reasonable analogy.  In the City's sanitary collection system, it was estimated in 2000 that 70-90% of the wet weather flow was coming from footing drains. Tackling that item first is very prudent and a reasonable course of action.  By addressing the 70-90% of the problem, it is very likely that the City significantly reduced the risk of basement flooding, and it is possible that the remaining sources of I&I do not pose a significant risk of system failure - we will know soon with the risk assessment and hydraulic capacity assessment.  Such an outcome simply would not be possible in your car analogy by only focusing on the oil.

-----------

"Robert are you telling us that the city chose to only look at fdds in the target areas? Astounding and incriminating."  

What is meant by this bolded word?  I do not appreciate the use of such a word, and would like to know what you meant by it.  This is yet another violation of the group norms - treat each other with respect.  Accusing a team member of doing something "incriminating" simply can not be tolerated. You have been warned numerous times of norm violations. Please follow them.

Frank Burdick on 23 Feb, 2014:

I did not bold any word.  It appears that OHM has in this posting and now this has violated group norms.

In addition, I did not accuse anyone.  If anything now OHM is accsusing me of something that I did not do. How does that fit the group norms?   

As for the use of the word incriminating, recall the question I raised at the last CAC meeting when OHM raised the issue about a treatment plant in Bloomington.  I then, cited a legal precedent provided by the Ann Arbor City Attorney where a municipality named Bloomington, was found liable for sewer related issues. I asked if the work being done on the OHM example was prompted by the legal case that was provided to us by the A2 City Attorney.

This particular legal case, made that city lialble because that city did not maintain their pipes.  That is what I meant by incriminating. 

Thanks

Frank Burdick on 24 Feb, 2014:

Regarding the comment above, "Frank - in your car analogy, all of the items you listed on the car are mission critical and could each cause failure of the system"

Ok, so I guess you want another analogy.  
This time you inherit an old wooden row boat.  It's been stored with hull of the boat, at the the stern,  sitting on the wet ground and the wood is rotted at that location. The boat has not been in the lake for years.  The fasteners and other seams attaching the wood to the frame all appear suspect.  You, however, just instruct the marina to fix the rotten section on the hull of the boat.  
Seems to me that any leak on this boat, no matter how small, should be addressed.  Either that or you just keep a few buckets (or sump pumps) in the boat to bail out the boat (wwtp) to keep it afloat.

In the case of the FDD areas, all leaking conveyance systems should have been addressed. 

Speaking of buckets, as for the statement, 
In the City's sanitary collection system, it was estimated in 2000 that 70-90% of the wet weather flow was coming from footing drains.
My research and review of this same study indicates that the only real test that was performed to make this statement of 70%  to 90% was based primarily on a bucket and stop watch on a few test homes.  Many other assumptions, estimations, comparisons to other  cities have been used to justify the fdd program in 2001 and beyond.  When you dig deep, it is clear that bucket and stop watch on a few homes 2001 was the only real Ann Arbor-specific test result. 

Robert Czachorski on 24 Feb, 2014:

"In the case of the FDD areas, all leaking conveyance systems should have been addressed." - this statement is simply not true. It is generally not cost effective, nor physically possible, to remove all leaks in a sanitary sewer system.  It is common practice to address wet weather flows in a sanitary sewer to the point where the risk of basement backups or SSO have been reduced to desired levels.

Rather than dealing with analogies, I'd rather deal with the real system. The risk assessment and hydraulic capacity assessment will be ready very soon. Then the CAC can examine the results and apply their judgment and values to the risks involved, the level of service desired, and the solutions to address those risks.  This process represents the standard of care in the industry for evaluating a sanitary sewer system. It is the standard for a reason - it is the appropriate way to evaluate and manage a sanitary system.  It is not a boat, or a car. It is a sanitary sewer system and we are following a tried and true process for evaluating it, consistent with industry standards.

It is my understanding that the City conducted a pilot FDD program and measured the flows by monitoring the sump pumps after installation. Regardless of the techniques used to make the estimates, they have proven to be quite accurate, as the flow removals were shown to be quite effective and right in the ranges estimates.  That is why the flow removal discussion has been parked.  

Frank Burdick on 26 Feb, 2014:

I would appreciate an "engineers" analysis of my statement noted above regarding bucket and stop watch test on a few homes.

How would an engineer not employed by the city or cdm evaluate that data? Ie: is it a true statement that the only Ann Arbor specific test was based on bucket, stop watch and a few houses?

I think it is important to determine how we got to this point with the FDD program. 

To use an analogy...  an auto engineer determined that a Corvair could be designed and effective to transport the flow of people.   Over the years a study may have shown that alot people flowed around in in Corvairs.  Sure they helped with the flow... but they were defective.  Sound familiar?

Lori Byron on 27 Feb, 2014:

Here are Michelle's questions posed at the start of this thread, along with responses from the City.

[CITY]
1.  Cresson, on what basis have these public officials in other communities formed their professional approval?

A: This opinion has been offered by past consultants working on projects related to the City’s system who have worked in other communities, not officials from other communities.  

2.  Is there a norm, a standard, or code (City, County, or State) for how Ann Arbor is responsible for surveying their system? 

A: There is no standard or code requirement for a utility to survey (i.e., video inspect) its sanitary sewer system.  The City’s goal is to video inspect its sanitary sewers within a 7-year period, based on available resources, to monitor their condition.

Lori Byron on 12 Mar, 2014:

A.    [CITY]
        
Benchmarking Ann Arbor's system against other sewer systems

In order to quantify the “tightness” of the Ann Arbor system, the consultant team will be benchmarking the A2 system to other sewer systems around the midwest that have been analyzed by the consultant on other projects.  This will show how the A2 system performs relative to other systems, and also help rank or prioritize the various districts within the city that have been modeled. This analysis is in progress and will be shared when completed.

Michelle Lovasz on 12 Mar, 2014:

Thanks Lori.  For Cresson:  Regarding the answer to question 2, I understand that the CIty's goal is to video inspect its sanitary sewers every seven years?  So, on some sort of rotation (I'm guessing?) each section would be video'd every seven years to monitor their condition?  Has this been done?  When is the last video inspection for each of the target areas?  Thanks.

Lori Byron on 27 Mar, 2014:

[CITY]

Field records indicate the latest cleaning & video inspection performed in the target areas are:

Orchard Hills   Cleaning  2011, TV  2011/2012
Bromley           Cleaning 2012 (some 2014), TV 2012
Dartmoor        Cleaning  2011/2012,   TV 2011 (mostly just Pauline)
Glen Leven     Cleaning  2011, TV  2011
Morehead      Cleaning  2013, TV  2011

Michelle Lovasz on 28 Mar, 2014:

Thank you Lori.

Judy Hanway on 1 Apr, 2014:

As a follow-up to the video inspections and cleanings:

Were any problems found? If so, what?

Thanks.

Lori Byron on 24 Apr, 2014:

A: The sewer videos that are performed are evaluated by staff.  Typically in any sewer system various degrees of deficiencies are noted. Major issues (such as partially collapsed pipe) are typically prioritized and addressed by Field crews. Other issues (such as root intrusion and varying degrees of pipe cracking or displaced joints) that need to be addressed in the system are prioritized and included in the Capital Improvements Plan (CIP) as future projects.

Michelle Lovasz on 30 Apr, 2014:

Hi Lori, thank you for the information about what the City's protocol is for the results of a video inspection. 

Were any problems found in the target areas?

Lori Byron on 9 May, 2014:

[CITY]

A. Tree root issues were found just downstream of Dartmor, otherwise no major deficiencies were noted for the target areas.  The area downstream of Dartmor was cleaned and is being programmed to be lined in the near future which will prevent future tree root intrusion.

Michelle Lovasz on 11 May, 2014:

Thank you!