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There has been some recent controversy about the planned Pickerington waste water treatment plant expansion. The actions of the city council and the service committee have been well documented over the last few years while this new plan for expansion was developed.
Why didn?’t we use the R. D. Zande plan of 2001/2003 that the city has already spent $575,000 on?
Answer: The short answer is that we asked that question a couple of times over the last year or so. The biggest problem we had with using that plan was that it would cost the city sewer users over $14 Million to build it as planned.
The second part of the answer is that in 2004 the city tried to do some quality engineering on the Zande plan and as of February of 2004 the Ohio EPA had not signed off on the new value engineering changes.
The third part of the answer is that in talking with a number of engineers and others, the Zande plan ran dirty water under the Sycamore Creek in two location and that was some of the maintenance issues we were trying to avoid with the new plant expansion.
The fourth part of the answer is that Zande required the use of a lift station near Stone Bridge that would have been connected to the 30?” sewer line out east of the City. After the sewer back ups in Cherry Hill in 2004 from an extended power outage I personally wanted to see us develop the Pickerington sewer system without lift stations if possible. The other half of that connection to the 30?” line was why would we be providing sewer service to areas of community that have not developed yet and more than likely will develop as houses in the future. It seemed more important to provide sewer service to areas within the city?’s borders that were more likely to develop as commercial in the next 10 years or so.
Then on the positive side of the decision making process we asked how much would it cost to just duplicate the current plant or double its current capacity? We hired Malcolm Pirnie to give us a ?“ball park?” figure of the cost of doubling the current plant.
Answer: They estimated for a new plant of 3.2 MGD that the cost would be around $8.8 Million. This for the most part was using the current technology and adding some enhancements. I will get into the enhancements below.
By Ted Hackworth
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WWTP
Enhancements to the planned sewer plant expansion:
Currently the Pickerington Sewer plant is rated at 1.6 MGD. That higher rating was the result of a stress test in late 2004 to show Ohio EPA that the plant could process the additional flow. The current technology is an activated sludge system. The new plans call for aerator tanks similar in size to what is already there. It calls for two clarifiers similar in size to what is already there and we plan to double the digesters. These tanks and other equipment will be placed on the higher elevation near the current tanks. This will allow us to use a gravity line to connect to the 30?” sewer line from out east when we decide to connect years from now.
The new enhancements being called for is a new head works. The head works in the Zande planned didn?’t meet the ten states standards of 1998 and the new design firm of Brown Caldwell recommended the newer version of the head works.
The second enhancement is a newer grit removal system which is sometimes called the wash tub system. I have talked with operators at the Orient State prison waste water treatment plant and they have recently installed this new grit removal system and they tell me it is working great. So it is proven technology and it has EPA approval.
The third enhancement is the tertiary filter and in our current plant that filter is a sand filter. We have had high dollar maintenance costs on this sand filter and it is showing signs of not working as expected. The new design will replace that sand filter (the Zande plan called for a sand filter) with either a cloth filter system or a fuzzy ball filter system. I have seen a demonstration of the fuzzy ball filter system and it removed an additional 40% of the solids from the exffluent going into the creek. The Orient State prison WWTP has recently install a cloth filter system so it is also acceptable to the Ohio EPA.
Because of the time constraints with a WWTP capacity slowly being used up we had to find a technology that would be acceptable to the Ohio EPA and an expansion with size and cost that the sewers users of the Pickerington plant had the means to pay for if future development went south.
The city hired the firm of Malcolm Pirnie to help work our way down through the different technologies available and to set the criteria for this future plant. There are some very good technologies out there but at this time the Ohio EPA has not signed off on them because of some operational problems that they are aware of. For the city to use these newer technologies we must first provide some additional hardware (aerator tanks and clarifiers) to gain more time to do the testing and collect the data on the newer technologies. With the fluidized IFAS system it has shown to remove much higher levels of nitrogen from the exffluent and this will help keep the creek from growing the algae that steals the oxygen from the creek. This technology is relatively cheap when compared to other methods of removal.
By Ted Hackworth
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WWTP
During the brain storming sessions with Malcolm Pirnie all of the available technologies were listed and each one was assigned an estimated cost. We even considered what it would cost to hook up to the Columbus Sewer system and after reviewing the Gahanna contract we decided that was not a good way to go.
In addition to the technologies for the selection of the sewer plant expansion we reviewed other factors such as: EPA approval process, capital costs upfront, Maintenance costs after the plant became operational, and operational cost in terms of additional man power.
1. The technology being selected is technology already in used and is already approved by the Ohio EPA. Even the enhancements are being used and were approved by the OEPA.
2. The upfront costs of using the current technology are the lowest costs to the city at this time. In addition it will allow the city time to test and utilize the newer technologies in the future. Those technologies will require some testing and the Ohio EPA will require at least 5 years of data before they will sign on to the use of these newer technologies. These newer technologies will be relatively cheap when compared to other expansion methods and older technologies.
3. Just upgrading the sand filters on the current plant will reduce both high maintenance costs and expenditures for those maintenance repairs. These sand filters are very labor intensive and the ease of operation of the newer filters will help in maintaining the current staff without any additional personnel.
4. This design will allow the WWTP staff to operate out of the same areas they are currently operating in and not require two different work areas.
Once the staff (I sat in on those meetings) moved to look at doubling the current plant and use the current technology, the City Engineer and the Staff Engineer wrote up the criteria for a request of qualifications of firms to design this new plant expansion. In that request they considered the priorities we agreed upon in the brain storming sessions with Malcolm Pirnie. That request was sent out and those company's interested returned their proposals. (It should be noted here that state law requires that we ask for qualifications and not an estimate for cost of services). In response to our request we received back 10 proposals. These ten companies were graded and assigned a numerical score based on the staff grading standards set up prior to the request going out. The top three scored companies were then called in for interviews with the Service Committee.
By Ted Hackworth
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WWTP
The companies selected by the Service Committee and members of Staff was DLZ/Brown Caldwell. The two references they gave in their proposals came back very good and they also scored high on the criteria laid out by the Malcolm Pirnie sessions. Ironically Malcolm Pirnie came in fourth on the list.
Once that was decided DLZ/Brown Caldwell met with the staff and worked out the cost for the design of the plant expansion. Their range of costs were from the high at $885,000 to a low of $682,000. The lowest price did not include the new head works. The city opted to go with the more accepted design of the head works to help meet the Ohio EPA requirements. So that design cost will be $774,000.
I know during this process and when we got close to awarding the contract there was a lot of heat coming from a number of directions. I know during the entire process the city was asked to consider many options and to keep an eye out for the future and for future expansions so that we didn?’t paint ourselves into a corner. The meetings and the thought process are well documented at the city and I believe the city and the council reached the correct decision here.
Finally the question of passing this design contract by emergency. If you all recall the plant expansion in 2003 was challenged by a referendum twice. Both were ruled that the issues were NOT subject to a referendum. The same would have held true for this ordinance. The ruling is that these are public works improvements and they were in a line of other ordinances that started the project long ago. If the citizens wanted to stop the sewer plant or the expansion they would have needed to do it some time ago. This is the very same ruling that shot the Diley Road referendum down.
Currently the City plant is processing around 1.25MGD per day on average. We have had some overflows in wet seasons and there is concern coming form the Ohio EPA. They have also issued the City plant 1.97 MGD in PTIs (permits to install) and with our drawn out process to expand the current plant we needed to get off the dime and move on our plans. It is my understanding that the EPA was pleased that we finally made the decisions and they have pledged to work with the city on the WWTP to keep us in compliance.
The process to decide what kind of expansion we were going to build is well documented and it is available at the City Hall. The process in selecting the firm to do that design was fair and those scores and the criteria for that selection are also well documented and all available at the City Hall. The emergency used to pass this contract was a real emergency because if we drag this out any longer we may lose some very needed commercial development in the city. I hope this answers all of the questions and controversy about this contract.
Thank you,
By Ted Hackworth
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