bio solids digesters facilities project update. >> good afternoon, cruz. >> good afternoon, members of the commission, assistant general manager of the infrastructure. moving from water to the waste water sides of the organization. we would like to present to you the status of the bi. o solids replacement facilities project. as part of the over all project, we set some objectives for what the project will do

and we wanted to make a modern treatment facility that will meet the reliability goals of service and meet the present and projected regulatory requirements to the extent that we could project them, and we wanted to change our product from the class b, product to a class a, product and we wanted to achieve the beneficial readings of 100 percent of the bio solid, and 100 percent of the bio gas and in addition to the technical goals, we want to be sure that we have to transform the community asset by doing a contribution, to the surrounding community, and minimizing odors and noise and traffic and during the construction to promoting training and opportunity of jobs for that community. >> we went through a, and we were in the middle of a process that started with planning in january of 2013. and takes us through the planning phase, and through september of 2015, and at which point, we will enter into the design of the project and that

the goals of meeting and slightly in the construction of january of 2018 and we have the general anticipated construction value of in the neighborhood of 800 million dollars on just the construction side. >> and to again, review what sfip goals and in order to provide a compliant reliability and flexible system to manage the storm water, and to be able to adapt to climate change, and to achieve economic and environmental sustainability in the plant and to make sure that whatever we do maintains repair and affordability. we looked at evaluation criteria, and we looked up technical considerations and we want them tied to our goals and adaptability, and the new and the energy, generation and we looked at greenhouse gas emissions and we looked up financial considerations and we looked up the cost of construction and the over all schedule and the operation and

maintenance and the technology and we tested the value of alternatives and the net energy pro-ducks of alternatives and finally in the other side of the triple analysis, we looked up considerations and obviously odor control being a huge factor and the stake holder acceptable of the final design and the greenhouse gas emissions as a result of the project and over all air quality and safety and noise and traffic use and the odor, control and we definitely are looking at a state of the art system and we have not landed on one and here is an example of something that exists in bright water, which have been able to achieve the zero odors behind the fence line which is our goal as well. to walk you through the analysis process, we started with the world of opportunities, and the options and we looked at everything that was out there in the bio solid world today and there, narrowed that down to four to five valuable alternatives.

and we then took those four alternatives, and one subset, and then, we did a further detailed analysis and got it down to two and then put them against each other to come up with a recommendation that we are moving forward with deeper analysis in order to conclude our alternative and analysis report. >> did you say scrub? >> yeah. >> so, we wanted to walk you through the alternatives that were considered. and but not advanced and in that kind of opening world of options. and we did look at aeroibic digestion, being the process that happens in an oxygen ated environment and we took that off of the table because it is an expensive process and uses a lot of energy and the generation of the oxygen necessary for the process and we looked at stabilization and the lines stabilization and we took that one off of the table because we do not know yet what the impacts of the final

product would be formed to line the introduced into this, and again, we wanted to make sure that we will achieve 100 percent of the reuse of the bi.. o solid and we looked at insin ration as an option and we looked at it because of the impacts to the community and did not want to pursue that option any further and we even looked at something called our super critical water oxidation, which is something that exists only in one plant, and i believe in florida. and what we will consider to be not the cutting edge but the bleeding edge, working through that technology and they had an explosion while we were considering that option and so it became fairly easy to take it off of the table. >> so what did we consider? we considered, four alternatives that we, that are what we say state of the art, and that would meet our goal and one of of our primary goals that is to make sure that we have a class a, bio solid at the end of the process, and the first was digestion, with

drying, and from the mechanical drying. and the digestion is what we currently do at our plant and it is an operationally, and it happens at around 100 degree temperature, and where they are familiar with that. and it produces a class b product by itself and you get to class a by post treatment after digestion, through a mechanical drying system. and not all of the different from your clothes dryer at home and you put the product in the machine and it dries it and comes out in a pellet format and the heat kills all of the bad passage in there and you come out with a class a product and it is a good product and it has the most reuse options of all of the items that we considered and it creates a product that is very easy to transport. and so the benefits of this one were the highest reuse options and the easiest format of the product itself. the challenge that is very

expensive and the cost associated with the mechanical drying were very high on the operation's side and both in the form of energy consumption, to one, and to actually power the mechanical driers, but also in the form of operation staff. we did visit plants and found that the mechanical drying was two to five times more expensive for the staff to safely one these dryers and that was one of the optionses and i walked through the four. them. and alternative two, started with the... >> sir? >> yeah, on that point, did you compare what revenue could be obtained by the sale of the fertilizer supplement and pellets >> we did. >> and offset the cost? >> it did not offset the cost in any measurable way. >> thank you. >> alternative to with starting with the same, and the digestion and non-oxygen environment and the oxygen free

environment and then accomplishing the transition from class b to class a through composting and this is what the city of chicago does, they have a massive composting operation as part of the process and the challenge is twofold, one is that you need, i am sorry, i didn't transfer. >> my apologies. >> you need a lot of land because you need to spread out the bio solid over a large area of land to get a thin enough layer in order for the composting to be accomplished and so we looked at two options one will be us buying the land and outside of the city and county of san francisco. because we would not be able to acquire enough land to have a successful composting operation and as the staff, this obviously had a high capitol cost of acquiring land and then the additional cost of transportation of the sledge, to the composting site. and we also looked at the option of contracting of the composting, and the county of los angeles which is just finishing the construction of a

large composting site, and it has far more capacity than they need and has expressed interest if we were to go this route to contract with them for our composting and our concerns not only that the transportation from here down to the county and across to the environmental impacts, but also, the long term cost and why we might be able to lock in a ten or a 15 year contract with the la county, what would those costs look like, 15 years on. and it was more unknown, and so we also saw this option as viable, but more sensitive, than some of the alternatives that we considered, which i will explain further. >> alternative three, is the temperature, phased anaerobic digestion, process, and it is a process, where you basically go through the digestion process and then goes through a second digestion process and this is similar to what the los angeles plant does and so they run

through a single batch, and send it through a secondary batch and then the secondary process, the last of them are killed, and you are coming out with a class a product and the disadvantage over this alternative is are that it requires a lot more land because you have to be able to built two sets of digesters on your plant in order to go through a second batch process, and again, a process that does produce a class a product. >> and then finally the fourth alternative is a new alternative to the united states. and this alternative exists in europe and has for a decade, successfully, and it is viewed in the united states, washington, d.c. has opted to go this route, about 4 years ago, they opted to go this route, they have just firning construction. and the commissioning in this next month. and in addition, hamp on roads in virginia has decided to go this route as well, and

stanford, is considering this option and it is called a they are mal hydrolysis process and this differs from the other three in the sense that it is a pretreatment before the digestion, rather than a post treatment after the digestion, and this particular process, you enter, and you put the sledge into this pretreatment process in the pretreatment it is introduced to high temperature and high pressure primarily induced by steam and it is once through a series of tanks and during that process, it is effectively acting like an autoclave, killing all of the pathogens, so that what comes out of the process is already clean and it comes out as a very high temperature and it has been cooled and entered into the digestion, and there are two primary advantages to this particular technology. and one, is that by virtue of the pretreatment process, it actually reduces the volume

necessary in the digesters and because it starts to break down the product in the pretreatment, and the second, is that as a result of that, your final bio solids ral value is also reduced and so it can reduce, the capacity needs, by 30 to 50 percent, and reduce your over all bio solids product at the end of your process by ten to 15 percent and not only produces a class a product, but it produces it and makes it more manageable for us to accomplish the 100 percent reuse. >> we did identify all potential reuses of the bio solids, and alternative and while, alternative one, offered the most options, also, alternatives offer all of the many options within the commercial market and we are comfortable that under any of the four alternatives we will have accomplished 100 percent bio solid reuse and, this slide simply shows the examples of what that product looks like, as a class a product at the end

and some applications. and over land applications for the product. >> so, in summary, we looked at the four alternatives, and we analyzed them for greenhouse gas emissions and net energy and annual operating costs over all safety, and traffic odor and air quality impacts to the neighborhood. and we found that alternatives three and four, performed substantially better than alternatives one and two. and generally, while they all performed well enough in traffic order and air quality, the areas of operating costs, energy, consumption, and greenhouse gas emissions definitely moved us away from the alternatives one and two into alternative threes and four. and we then took a second analysis and more deeper than the alternatives three and four and looked at deeper analysis as to with regard to the robustness of the industry, trends and which way the industry is going as it related

to the two alternative and over all operations and maintenance of the type of technology. and reuse of the end product, and the reuse of the bio gas. and adaptability to the regulatory changes, and ability to insure that there will be not be regrowth of pathogens in the bio solid and the construction schedule and the digester volume, looking at the two alternatives three performed well enough that alternative four was clearly the winner in all of these alternative and all of these selection criteria. then we made sure that we went back and compared that analysis to the initial goals that were set and you can see that in every goal category, alternative for the positively allows us to move to the goals that were set by the commission. in summary wha, we do today is that we have a gravity belt

thickener for our sludge and we enter it at about five percent solid, by volume, and into our die geters. and then, what comes out is a class b, product that we put into the interfudges and it is a class b product and it the new technology will add the pretreatment. and a couple of changes and, one is that we would further craoen and include the cost of this and further screen the sludge to be sure that we had taken out all of the non-organic and the sandy grit that we get in the system before turning into the sandy or the hydrolysis process. and once, the process, again, it is sterilized and reaches 300 degrees in the tanks and then we need to cool it off before it goes into the digesters perform at 100

percent and so we include the cost and the technology considerations for the cooling and the heat transfer system that brings it down to the 100 degrees and once it comes out of the digestion, then we go through a thickening process and come out with our cake. the other benefit of the process is that it does generate energy. and energy, that between that, and the digesters which we will then reuse, we will reuse on the site, and plan to use them reuse on the site and the energy necessary to generate all of the steam to recirculate back into the thermal process and so that it in fact, will be self-containing and generate enough energy to generate enough steam to keep a circular loop and we will have the gas that would be converted to cng and electricity and which will offset s costs associated with the over all operations of the plants.

in a very simple analysis, after spending many and it will be a lot east tore eat, but it will be raw in your stomach and hard to digest, but your body

will digest it, and take the same and boil it and mash it and then eat it and it is easy consume and it is easy to digest, that is basically what the process does, and it pretreats this sludge, so that when it gets to the digester and the bacteria have a very easy time digesting, and it breaks it down, but virtue of the temperature and the pressure at the mow molecule level and it takes fewer bugs and they eat it more completely and we get less bio solid and so it is a pretreatment for the typical digester that makes that job that much easier. it is a technology as a said, that exists in europe and has for ten years and successfully, and we did, do due diligence and go and visit three plants

one in ireland, where it first went in ten years ago when it went in it had the challenges and the company that owns this technology came back in and modified the plant and to the own satisfaction everything from on door control and maintainbility. and we also visited, london's crio plant and manchester's yet's room plant, and the other major thing and then finally we ended the tour, actually going to oslow where this technology exists to meet with the ceo and the chief of this particular technology to go over the company's due diligence, and one of the things that i will say and i was impressed with is that the company has clearly taken its profits and put them back into the research and development and they continue to make the product better and we continue to make it more affordable *fbility to the point that washington, d.c. if we did decide to go with it and it took two years to construct the thp part of their four

billion dollar expansion, at blue plains in washington, d.c., and the technology now that they have advanced to the newer operations are 60 percent smaller and 40 percent more efficient, and they were installed in manchester in three weeks and so they have gone from a two year installation to a three week because they continue to make the product better, smaller and more efficient and more reliable and every operator that we spoke to had nothing but good things to say and they were all completely satisfied that they had made the right decision and talked about taking other plants that they currently had and retrofitting them to this particular technology. and so we feel comfortable moving forward with this, this is an informational presentation, and to let you know that this is the direction that we are going. if we do move continue to move forward in this direction we will continue to have the alternative analysis report by

the end of this year and bring back to you, a report, asking for permission to move forward into the environmental phase and into the conceptual entering phase to move project forward and i would like to commend the staff on the puc side as well as the other side and they have been working on an aggressive and he would and they said that it would take six months longer than where we are today to get to where they are and i challenged them to cut that schedule by six months and they have worked at a very fast, but diligent pace to do so and so we are six months ahead of where we would likely be, if not for all aggressive work by both our staff and the consultant staff. >> and with that, i would like to conclude my presentation. >> commissioners? >> yes. >> commissioner torres. >> the technology that you cited and alternative number for, when you said that the

waste is consumed before it goes into the final drawing. >> yeah. >> is it consumed by what? >> what it is is it is broken down. so it is not consumed but it is by virtue of being introduced to the high pressure and the high steam, the sludge is broken down at a moleculer level and so when it enters into the digester, the bacteria that we typically use for the digestion process has an easier time to consume it. and so that it makes it easier for the digestion process, therefore, making the digestion process more efficient and more effective reducing the over all size of the digestion that we need and reducing the over all product that they have. >> and emissions. >> and emissions yes. >> and the bacteria that is used in this process and that is similar to the bacteria that is used in the oil spilled consumption. >> i do not know sir, i do not

know what is being spilled. >> but the bacteria that we do use, in the digestion process which is a mesofile is a very, standard, type of bacteria that we use in the industry and i have an example and in los angeles and chicago where they use the digestion, they use the same type of bacteria. >> commissioners? >> commissioner vietor? >> so, food waste? >> the... >> does it have the capacity? >> the technology, that we are building has full capacity to handle the food waste and in fact, in oslow in addition to meeting with the company, that owns this technology, we did tour a plant which is a food waste only plant. and it is a plant that was built to take all of the food waste for the entire city of oslow commercial and residential and generates energy, that is then turned into cng and fuels and the

public fleet. food waste, definitely produces a lot more energy, by virtue of the process. and, so there is a lot more positive to it. and our challenge as we look forward is actually to handling of the food waste. you know, again today, the city has a contract with them to actually pick up the food waste, and recology has indicated that they do not have the capacity to segregate the food in the city and so they transport it by truck and they are planning to build a digester in vacaville and to feed the fuel of the truck that are being used to transport. and so we have the capacity, for high strength waste, and if we were to get a full high strength waste, we can certainly process it, but challenges that we see, and that we have seen everywhere

including in oslow is for the high strength waste to be effective it needs to be 100 percent organic and there needs to be a diligent process prelined to be sure that none of the organic processes have been taken out, the most common are forks and knives and plates that have been thrown in on accident. >> and is that different than green waste? which might have even more potential? >> we did not look at green waste, as an option. and none of the plants that we went to, processed green waste. but i can tell you as an example, daily in manchester, one of the telling things from him in speaking to the head of operations there is that they said that they wanted and they used the different terminology, but basically it is class b and class a and they were producing a class a product and brought the process on board to get from class b to class a, but, in doing so, they so much

improved their ability to generate the bio gas and generate the electricity as a by product and they considered that we used to operate like a bio solid plant that had or used to operate a processing plant that produced bio solids and we now operate a power plant that happens to use the solids to generate energy and to the point where they now, and outside of the daily processing, they truck in 30 percent of the bio solids from other facilities just to process for the generate energy. >> that does not include green. >> yeah. >> sorry. and so the waste currently, that we generate, in san francisco, that we would process at the treatment facility, you said that it would be closed loop and so it will be able to sustain itself. >> yeah. >> from the steam. >> and do you know how much currently there will be extra and if it could power the entire facility?

>> or... >> we don't know that yet, but we do not think that there will be enough energy to actually take the facility off of the grid 100 percent. but we are looking at numbers in the neighborhood of 50 percent reduction in the electricity requirement but we have not gotten to that level of analysis, but, on that vein, in that vein, the thp process we are recommending is the one that does generate the most use of energy. >> yeah i would love to learn more about that as you have learned more. >> yes. >> and to hear really what the capacity could be. and wonder if we did add, i don't know what you called it the highway street. >> and the waste to that traoem if there could be some real bump in energy production i think that would be quite interesting. >> yes. and part of the analysis we will do, is characterizing the traditional bio solid that we have and the likely energy output and we can do the analysis with regard to changing the composition and seeing what effect it might have, and we could then apply

the cross benefit analysis to what it will take to segregate out effectively, and bring it in. and we have been having conversations with recology because they are definitely moving forward on their course and the good news being, that under any scenario through our conversations the high strength waste will be converted into either electrical or cng reuse. >> okay. >> one last question. >> and then the end product, it sounds like they will have a high quality, class a product at the end of the day and what is the plan for that? >> we are looking at options, you know, we, it certainly has a land application, and reuse options. and we are looking at whether we simply provide it as a fertilizer for growers primarily in the central valley or if we try to actually have some reuse ourself, we did go

visit the los angeles city operations where they trucked their solids to a land that they purchased outside of bakersfield and they do land application and they do the crop growth for land human consumption and the crops like sf for miol and corn and then sell those crops to the local dary farmers as feed for the cows and so, we can either look at that type of reuse, or urban agriculture, or, traditional fertilizer as well as typical land, and landfill cover. >> when will you have more information on sort of what those options might be? >> we know that all of those options are open to us and right now what we are investigating is the land availability and the consistent user of the salt. >> so it will be in all likelihood, during the cer phase. >> okay. >> in 12 months. >> great.

>> vice president caen? first of all i want to share what a fascinating presentation, really quite something. >> thank you. >> i am sure that this is too soon to ask, but do you have any preliminary comparisons of cost of the four alternatives? >> actually, i any neglected to mention that we looked at at the four value and found a ten percent differential taking all things under consideration and so as an example of the alternative one we had a buy the mechanical dryers and the thermal hydrolysis and surprisingly all four alternatives were within ten percent of each other and so we did not find the construction costs to be a differenter that made it one alternative greater or fallout or we did see the differences in the operating costs and all alternatives were in the neighborhood of over all s