doing in the system. and as you moved into the end of the year, we were getting about 78% from hetch hetchy and alameda county and 22% from san mateo county and the slim .3% from groundwater. in march of this year, we were doing about 70% from hetch hetchy and alameda county and 29% from san mateo reservoirs, and about 1.1% groundwater. then this is the most interesting one here for the period that ended on april 1 of this year, the amount from hetch hetchy and alameda county was only 20%. it was a very small piece of the pie by comparison because we had actually taken the hetch hetchy system offline for maintenance during that period. so the vast majority of the water in san francisco was actually coming from the san mateo county reservoirs at that period about 78% and about 2% groundwater during the heavy

testing period for the central golden gate parkwell. again, the blend changes not constantly, but it is changing every few weeks as we do something different in the system. and we worked really hard to make sure there are no things that people notice. generally people don't notice the changes in supply and that is something strange happens like happened back in 2016. we had algae in the reservoir and that ended up with a two-week period where there was nothing we could do because it was all in the system. we had taste and odor issues. once we got it out of the system, things were back to normal and just as a quick aside, we are starting work on a project to actually o zinate the water which is the silver bullet for dealing with the taste and odor issues, so we should never face than again once we complete that project. a look at the water quality data -- >> i can just -- excuse me.

the groundwater into the reservoir at a certain rate. as i look at the pie charts and increasing to 1.1 groundwater with the increased gallons coming from the reservoirs. >> is that correct? >> and the san mateo county reservoirs with the crystal springs and that is where the majority of that watter is coming from. and so this increases over time for us. and blended in with that water. and with the concentrations coming in. >> that is why i am a little

confused. if i am looking at the two chart, it is almost doubling the percentage of ground water. >> from 1 to 2.1. and the percentage of the san mateo reservoir border has gone from a little bit more than double. >> from about 29% to about 78%. that is because we went from 29 to 78 to indicate that the groundwater should have gone up even more. and this is basically the total supply and each of the charts presents 100% and with san mateo county and 70% and hetch hetchy and 1.1% was groundwater. >> and the groundwater is

blended into with the supplies in the reservoir. >> the percentage of groundwater in your san mateo reservoir should be consistent. >> not necessarily because we had cut way back on the hetch hetchy supply there in the april 1 period. and we peaked up the delivery from the san mateo side and with the demand -- >> a let me try another way. >> the demand in the two periods is about the same -- >> i get it. i am focussing on the ratio between groundwater and san mateo. if you do the math, this is just guessing on the math right here. the 1.1% with 29.4% with that

groundwater coming from san mateo, right? >> it is in comparison to just the san mateo county water, but from the same set of pipelines, a certain amount of hetch hetchy and alamedo county water as well. that is part of the blend. not just san mateo, but all the water that is blended coming into the city. >> okay. >> so it's that you could say basically the golden part and the pale part together is what's coming into the city across the city line into san francisco. regardless of the source of which was the water coming from outside of san francisco. >> can i just because i started asking -- >> sure. >> -- and this has nothing to do so much with the drinking water

itself, but there -- can you take groundwater? i don't know what percentage we are trying to pump out compared to what is already down there as groundwater. and as you pump out too much with the adverse effect in the environment around there? >> there are two types and one is from a salty body of water like the pacific ocean, if you pump out too much, you drag the salt. and one of the things about the design of the project is the flow of water is typically out into the ocean and the pressure pushes water that way. we are taking a little water off the top to skim that down, but not enough to create that inside. and one of the things we have the program is a line of monitoring wells and along the

coast and monitor routinely for salt to make sure that we are not seeing any adverse concentration and so far we haven't. >> there are plans for the future and to increase how much out of the groundwater. so i am worrying about that. >> that is an excellent thing to worry about and that is the single biggest problem with groundwater is overdrafting the sucks in the salt water. it is not an unlimited supply for us. we might have a slight increase in drought years, but not a big increase in drought years because the basin cannot sustain that without doing damage to the basin. and killing the basin would be the worst thing we could do. >> i guess you've probably have done some engineering studies to sort of know that balancing point. >> that is probably the single

biggest issue which is taking the 20 years to really understand so we think we know it as best we can. what we are doing now by turning the system on after we constructed it is getting the real data and we will be cracking that carefully. >> can i ask a question please? >> so i am trying to understand this blend. so where does the water come from in the alamedo and san mateo and hetch hetchy and rainwater, right? >> so hetch hetchy water comes from yosemite and comes across the valley and comes in through irvington tunnel into the system. and it's joined by waters from calavaris and san antonio reservoir which are in alameda county and the water in those two reservoirs is filtered in

the snow valley water treatment plant. that water comes from the local drainage, but also some of san antonio water is previously stored hetch hetchy water when we have excess and we store hetch hetchy water in that reservoir as well. those two reservoirs we refer to as the alameda reservoirs. on peninsula, we have san andreas and crystal springs reservoirs and pillar seal which are the local reservoirs there. particularly crystal springs is local drainage and san mateo creek, but it always sometimes gets excess hetch hetchy water that we can afford to store there as well. so each of the local systems gets some hetch hetchy water into it as well. the total on balance is about 15% local supply and about 85% from hetch hetchy. >> and the local supply, again, how does that get there? like rainfall? >> a rainfall that is with the drainage basin. and built in 1888 to capture

local water for delivery to san francisco. that is what it does primarily. >> what are the quality differences between the three sources? >> yes. there is an overflow room in the chamber. and so i think we are trying to ask people who don't have a place to sit to move to the overflow chamber. thank you. continue please. >> a speaking to the quality of

the different sources and one of the things that san francisco is blessed with is on peninsula the watersheds are owned by san francisco and no extra sources of pollution there. the water and quality of water and the reservoirs is almost as good as hetch hetchy water. very hard to distinguish the difference. the same is true of the alameda reservoirs because we control a lot of the land there either directly by ownership or by agreement with local farmer there is. who are raising cattle and are probably better than any other in the state except for hetch hetchy. but collectively they are all very high quality water sources. >> thank you. >> and speaking of quality, one

i wanted to talk about the quality of water particularly in sunset reservoir as of april 15. we have three parameters listed here which are ones that are of concern. hex valent chromium, and often chromium 6, manganese, and nitrate. we have test ed for each one of the parameters and 103 for manganese and 153 for nitrate. the next column show what is the maximum contaminant level is which is basically the drinking water standard. you cannot serve water that is above the concentrations. but the average concentration of what we've seen of these parameters is in the right-hand column. and they are all far below the drinking water standard for each of the parameters. again, that is due to our, a., the high quality of the water to begin with, and the treatment and blending strategy that we exercise in putting water into the system. >> so this is from blended water or water -- >> yes, this is from blended

water. >> do we have the information on the actual water being taken out. >> this is the water from the reservoir? >> we don't have the values being pulled out of the ground? >> a we have those as well because we also sample the wells periodically to make sure what concentrations are there to make sure the source isn't changing in concentration. >> so what are those concentrations and have the concentrations ever neared with the average plus blend and what really are the values for the water when it comes out of the well? and does that ever approach the maximum contaminant level? >> an i think there may be one well for nitrate that approaches that level and again, blending it down makes it virtually indistinguishable from the rest of the water.

otherwise i believe everything is below the maximum contaminant levels. but we can provide the data that we have collected for the constituents in the ground water. >> ultimately what percentage and you are talking with the value within the well can occasionally be close to the permissible level and average the fine, but with the drij of water, they should have some certainty of what they are getting. as it increases, we could overshoot and we could have the water with higher concentrations. >> the quality of groundwater does not change rapidly.

basically it is large underground reservoirs and tends to change slowly over time. we have no expectation we will overshoot. because we have the m.c.l. we have to meet and target levels below those which are the operating target levels to make sure we don't exceed those. that is what we use with the standard with half or less of the drinking water standard. and that is also to go verify what is happening out there and watching the system and monitoring to make sure that we are meeting the standards that we have to meet and better. >> and looking at this column over here, what is the

recommended level it should be below. >> should be below the maximum contaminant level. >> and that is the maximum when you were testing. with the lower end and high end? >> that is the average there and there is the data which is the stshd set by the state not to be exceeded in drinking water. >> and is shown a little bit higher than the others in the

nitrates and ranging from 54% to 60% of the maximum. i guess part of the what i am concerned about and this source coming into this big pool. at some point that water goes out and we are drinking it. and what percentage goes into the drinking water so it is not like you have a big blender. >> we have an awful lot of turbulence and designed the system with the blending to take place and that short-circuiting

for different reasons is bad because if you get short-circuiting of water coming in the system and going out, that means you have aging water on the side. and aging water starts to have its own problems. and the longer you let water sit, the worse off it gets. we work real hard to make sure that it is maximumly blended as much as possible by where we have located it. >> thank you. nice to know that there is a blender there. >> we don't have a switch. >> by the way, i want to acknowledge dr. gene wynne -- wintrop. she is the chief who is here to answer questions as well. >> thank you for being here. >> thank you. >> so really in summary with the addition of san francisco groundwater, we have continued

to meet all state and federal water quality standards with no change in the introduction into the ground water supply. we are taking it slow so that the statements are true over time because that is our goal. >> and i have one more question about the contaminants. are there cumulative effects if you keep on drinking it? and is that impacted? the same thing if you have -- and have a little bit, but it stays in your body. and is that what this stuff is? >> actually, that question is better posed and i don't know if you want to do that now or wait until i finish going through the rest. >> why don't you finish up.

>> and i want to talk about the outreach and which we have done more of and also about the groundwater storage and recovery project. in terms of outreach, again, we have been at it for 10 years and the focus groups, media coverage, newsletter, utility bill insert, planning department, of course, and their processes. and producing fact sheets and we have material available at our website. and providing data updates since july as working with members of the community who have expressed concern and we committed to and remain committed to sharing the data so everybody can see what we are doing. we have had a lot of social media impressions and constantly updating fact sheets and i personally have done a number of

presentations to groups throughout san francisco and over the last year or so. and as well as other staff. and in doing a lot of responding to questions from lots of folk. we really think we have reached a lot of people in san francisco since last july. now i am going to shift gears to the other project which is important for drought purposes by itself. this project was designed for providing drought protection for san francisco and the wholesale customers. as a partnership with davis city, san bruno and calwater that provides additional local water storage equal to the crystal springs reservoir. the way we are doing that is by delivering excess surface water in wet years to the folks who use groundwater down the peninsula and then basically have stopped using the groundwater as much. and that is allowing the groundwater basin to rise and accumulate more. there is a lot of vacant space there that can be used for

storage. the whole project is designed and still has space in wet years so that we can draw it down and dry years to the normal level. and so really that reliability will be getting out of that. >> how do you fill that space? >> basically you fill the space by stopping taking water out of it. water naturally will flow into underground aquifers and we have measured that in this lower part of the aquifer. the san francisco part of the aquifer stays high and is pushing up to the ocean. this part of the aquifer has been pumped by the cities as well as the cemeteries and golf courses down there, so it's been lower over time so you get rebound. you start pumping water out of it and it starts to rise slowly from the natural infiltration. >> we are replacing the groundwater with hetch hetchy water so they can restore the aquifers. >> it is a shared aquifer by all of us. now we're part of the group

installing wells there. the orange dots are new wells that have been installed in the lower part of the aquifer and the southern part to contribute to the overall supply for the northern peninsula and san francisco in times of drought. >> so we basically are expected to see construction of the 13 wells we have slated there. and this calendar year. and we will be doing the startup testing of those wells. i think we will do the startup testing to definitely be backing off the san francisco groundwater wells while we test those wells in the area and this is a diagram that shows, again, where the water comes north of

from the three reservoirs in san francisco and with the groundwater coming from this project in times of drought will go to everybody in the city with that part of the project and that will be experienced during the testing program. but the project is going to be reserved for drought conditions. that is when we're really going to need that extra supply to survive a drought. that is part of the basin that has operated differently than the san francisco part of the basin. that is where we have and a lot of information about the groundwater projects and the local water program for water quality, the west side and f.a.q.s and environmental documents on the website. with that, we can go to questions and i can answer more

questions and have dr. winetrop to come um to answer questions, that would be great. >> an i am sure we have quite a few public comments, but i do one question in terms of the cumulative effects of the contaminants. >> hi. good morning. i'm jean winetrop and the senior epidemiologist and the manager of the water regulatory programs at the san francisco department of public health, and specifically the environmental health branch. so i have more than 30 years in background and water supply and wifb i have been with the city for 17 years. that is my background for you. specifically to the question about what is called bio accumulations and whether what happened, for example, with mercury and fish, if you have a fish swimming around and it eats up plankton that has some

mercury in it and a bigger fish eats that fish and it has eats three of those fish and now it has three times as much mercury. and then so it accumulates and never goes away and when i eat the fish, i get a lot of mercury. that doesn't happen with the come tam nants that we are talking -- that doesn't happen with the contaminants. they all get metabolized in different ways and that goes a little bit beyond my area of expertise trying to actually explain how each particular one get gets metabolized within the human body, but that is where we have to have faith in the regulatory rudiments. they are developed by smart people. that have been the place for a long time and they are

constantly being re-evaluated. i heard a little scoffing behind me about the faith and i do understand. there are many people who do not trust the regulatory process, but i have had the privilege of working closely with a lot of the individuals who do that work and i do have faith in them and the maximum contaminant levels that the p.u.c. tries to not just abide by and set targets that give a real level of comfo comfort. we are living in a time where lay people can look up things and smart lay people who have lot s professional things. >> thank you very much.

>> you don't have to defend yourself. >> that is my soap box. >> there are only three contaminants that are listed here. i am sure you are testing for other ones. are there others that we should be concerned about? >> steve can speak to the many contaminants that are regulated by the safe drinking water act, and they are required to test for them routinely in the annual reporting and other various mechanisms, they have to report when they have excursions and the reporting that's happening on the web and i think it is just the three that people had been specifically interested in. >> there are a whole array and some are on an annual basis and

quarterly basis and some are on the longer timeline. and the biggest worry is salt and that is when we monitor for very frequently and in addition to the routine monitoring, we also have a program that we participate in with the programs of concern and everybody believes three years and go on an extensive testing program for all kinds of things that there are concern about and maybe regulated in the future. we try along with the e.p.a. and other water agencies to be ahead of what is out there in the environment. and if there is something we didn't know about, we are looking for more things to make sure we are continuing to serve that product. and there is a lot of different things. we have extensive data reports that we do a data report annually and we have a large report done by consulting firm and putting together as we

started to look at the contaminants that we might see in the groundwater. and reviewed everything and just where we came up with the targets and chemicals of interest manganese, hexavalent chromium and nitrate. >> thank you. go to public. [calling of speakers]

and anyone that follows that, be ready. and the overflow room, we will be readily in about 10 minutes. >> good morning. i am here on behalf of spur to once again support the sfpuc's groundwater blending pron ining. thank you, steven, for the updates. this is an important part of diversifying our city's water supplies which improves reliability, sustainability, and resilience for the whole regional water system. as we have heard, it's been in the works for more than 10 years as part of the city's commit tonight the water system's improvement project. this is something that spur has also supported for more than 10 years. so testing and monitoring of groundwater quality has repeatedly shown that this water source is safe to blend with our hetch hetchy and other local supplies. together this blend will exceed

state and federal water quality standards. both the sfpuc and the department of public health have attested that that plan will not create any adverse health consequences. the groundwater program is part of a larger diversification effort with recycled water and adds local watter to the portfolio which will be reliable as we heard even during a drought or afteran earthquake. groundwater is part of water supply all over the world. 80% of the californians drink groundwater, and the same groundwater basin that the sfpuc will be using under the program was used for drinking water in san francisco in the past. and as we heard, it has been used by other bay area cities include san bruno and daly city for decades.

spur urges you to allow continued implementation of the well vetted and long-standing plan. by closing this hearing without further action, and by -- >> thank you. >> thank you. next speaker please. next speaker. i have richard. >> good morning. i am the president of the coalition for san francisco neighborhoods. and the first i want to start

with definition. i am tired of hearing about blended water. i think what we really need to do is have a new definition of taking the best water hetch hetchy and blending it with the lowest quality water available to the city. so that's my definition of what we're doing. and as to neighborhood outreach, a day and a half ago many of the people that saw you a year ago were contacted by supervisor yee's office. there would be many, many more people here had they known that you were even having a committee meeting today, and they will not have a chance to talk or say anything. i would like to say many of the wells that were going to be started were not start ed.

the amounts that have been used have been so minuscule most of the time to be tested and is an average of an average of an average, and so you basically are not looking at the real impact of what is happening here with the water. i think this has been done poorly and not done well and the outreach has been done poorly and not done well. or we would have this room packed right now. i wish i could talk longer. >> thank you.

>> i would have appreciated going 36 hours and they did not generate that report yesterday, so this is unfair. also, i would like you to take a look t a the fault line here. we are building the emergency fault line on top of two major faults. that is really a smart thing to do. so if the fault, if we have a major earthquake, which we will, what happens? what happens if it breaches the aquifer? now, that isn't going to happen?

well, fukushima didn't happen either. and we have a plan based on hope and luck, and hope and luck is not a good long-term plan for the city. the groundwater is legal. that doesn't mean it's safe. lead was once legal. put lead in gasoline and breathed it up until the 70s. d. d.t. was legal and safe. most of the time the e.p.a. changes the standards and they lower and lower them. and the comments that nitrates and chromium are safe is a comment made at our level of ignorance. nothing else. why do we claim it's healthy? i doubt it. and we consume our drinking water around once you consume a billion gallons every summer, there is a billion gallons less if you ever need it.

new technologies is doing not a lot. in phoenix, arizona, there is a company that's generated zero mass to generate the drinking watter from the entire family from the air in the desert. i heard nothing about technology. groundwater is not new technology and there are huge events. >> good morning. i serve on the san francisco public utilities commission and citizens advisory committee and chair the water subcommittee and an original member and i worked on prop e in 2002 and helped write the legislation with the advisory committee. and public engagement and public notification is really important to me. and it is something that i have been trying to push the p.u.c. on for about the last 20 years. and i agree 36 hours notice of a

hear i hearing # isn't really good and we should try to figure out how to more broadly notify people. what i would also say is i work as at whatter policy expert. i work for clean water action and the specialties are drinking water quality and groundwater. and honestly, i think the groundwater is pretty good comparatively speaking. and i think that you're blending -- the way you are blending is much better than a lot of areas do it. generally you pump the groundwater and deliver it to the area close ye to the well. and the amounts right now are very small. what i think is appropriate for you to consider is are the maximum contaminant levels the reference levels for blending. and you might want to look at the public health goal which is the level at which the office

has determined that no adverse health effects of cur. it is the same as the contaminant level 45 per million. manganese doesn't have a health level because it is actually regulated because it tastes bad and is kree yating particulates. -- and is creating particulates. and the level is about 50, so that is a text taste and o dar issue. and the public health level for that -- >> supervisors, i am chris boman on the steering committee of the san francisco clean water

coalition. eng, if we had had -- again, if we had had earlier notice of this, lisa brommel would have been able to attend, but she simply couldn't do it, so i have to serve double duty here. the maximum contamination level per a lot of con tam nanlts has been made -- of contaminants has been made more strict over the years. if you look at arsenic, for instance, it's basically 1/5 of what it was previously. so it's five times more stringent. there was a professor at the texas a&m university who did a study of birth defects of 3,000 women in texas and in iowa. she found that at 1/10 of the m.c.l. per nitrate injegs, the chances -- of ingegs, the

chances were twice the rate of the m.c.l.. when we get a 15% blend, which is what's being proposed, which is basically four million gallons to about 24 million gallons of hetch hetchy regional water system. and that we could have nitrate levels at double the level that creates birth defects. so the other thing is you have to look to talk about using this for emergency purposes and the north lake and the latest groundwater quality report that you put out. and the north lake well, which will be use d at 94% of the m.c.l. and were nitrates. and the ones we were talking about like we said, 54 to 60%. and once you run out in the emergency, we have a nine-day supply.

are there additional speaks? people in the overflow room, they are welcome to come to the chamber. >> good morning. i am the secretary on the san francisco public utilities commission and i sit on the water and waste water subcommittee. i am here to provide support for the supply water project. i think it's important in terms of diversification of our supply water sources to insure longevity for future generations to have reliable, high qualitying a sesz to water. -- high quality access to water. i am thinking about cape town currently when they are nearing the day zero coming up and they have focused on conservation and didn't invest as much into other alternative sources such as groundwater and such as recycled

water. so i support our diversification efforts. i did have a look at the recent data that was published by the sfpuc and i actually looked at the higher levels and they provide the average, but had low and high levels as well. and specifically since everything seems to be interested in nitrates, i looked at that one in particular. and so in terms of the data that was just provided, those levels were 93% and 99% respectively for sunset and sutro reservoirs for their high levels of nitrates. so in conclusion, i am here to support the groundwater project and i ask that you do the same. thank you. >> thank you. next speaker please. >> i wanted to show you a number of things. the project was originally started on the assumption that we were going to lose jobs

because there was not going to be enough water. instead, we gained 125,000. and this is the chart from the amount of water we used in 2016 which is what we used in 1972. >> groundwater has nitrogen in it and that is considered an carcinogen. from the working group the following quote can be found. unlike virtually all other con tam nanlts, the -- like all other con tam nanlts, the drinking water for nitrates contains no margin of safety. nearly every chemical standard enforced today incorporates that safety factor to insure that

sensitive members of the population are adequately protected. when there is evidence of possible human cars motion carro genics, there is another to tenfold factor. the nitrate standard contains no safety factors even though it is targeted to the especially sensitive population subgroup, infant, and even though nitrates is a precursor compound to the formation of cancer. in europe the safe level of nitrogen is considered to be 4.4 parts per million. i'm sorry. 5.6. and in south africa, the amount is considered to be safe at 4.4 parts per million. this discrepancy --

>> thank you. next speaker please. >> hello, supervisors. eric brooks. i started as a consumer watchdog activist with ralph nader's public interest research groups and grew up in the sierra mountains in bishop, california, where we were battling my entire life and los angeles stealing the watter from the mountains all that time. i am a strong supporter of cities using their groundwater, but i do not support this project because it is not safe. i want to conduct through some of the satellilight of hand and major is saying, oh, groundwater is okay. look, in this other reservoir and the other areas of the watershed, groundwater goes into the water supply all the time. the difference is the

groundwater is filtered before it's sent into the drinking water supply. what the sfpuc is about to do is blend water into the water supply which could at any point in the future become contaminated by an emergency or by something we do not notice is happening to the groundwater without filtering it. they're just going to do minor biological controls. this water either needs to be used in golf courses or parks and irrigation or filtered with reverse osmosis and u.v. light to make sure that it's the same quality of the water that we've got now. blended and this argument that is okay because we are going to blend it is not how san francisco approaches environmental and safety issues and if we start now, we will end

up like flint, michigan, and the other california cities. this is a mistake. >> thank you. do we have additional speakers? >> if there are no mr. speakers for puck lick comment, public comment is closed. i did want to ask about the contaminant identified for which we have no value currently. i think it was hexavalent -- and i forget what the other half was. >> that is the state water resources control board proposed and adopted a drinking water standard for hexavalent chromium of 10 parts per billion three years ago. they were sued by i believe the

up to of vacaville because that standard and there is hexavalent chromium that appears naturally in groundwater in many cases. we have some in our groundwater that occurs naturally. and so the vacaville case basically challenged the process for adoption of the standard. and so the corps found that, yes, they did not properly adopt the standard and they are going back now and starting the process over to consider what the drinking water standard should be. so currently there is no standard for hexavalent chromium. >> so what are our values for that contaminant? unless that was under chromium. >> and chromium 6 is hexavalent chromium is the standard term

for it. and the maximum shows .01 milligrams per liter which is the same as 10 parts per billion, but that standard doesn't exist, but it is there for informational purposes in this slide. but what we have seen in the blended water and sunset reservoir is .00017 milligrams per liter. and far less than that standard if it were in effect. >> great. thank you. >> i'm sorry. can i ask a question? do we have the numbers for the other reservoirs or sources of ground water supply? >> we have data on all the sources of the water supply and sources of water supply. >> from this other supply, are they similar concentrations? or different -- we have one example here. but it would be interesting to see the other sources of ground water and happy to see

substantially below the maximum contaminant level as set by the state. and i would love to know that -- >> the targets that we have set which are lower than those. and nowhere near the maximum contaminant level. we can provide all the data that we have for the sources of supply and hetch hetchy and the bay area reservoirs and the groundwater recovery project as well as for this project. we will be reporting those out now new future and ongoing and that is the obligation and commit tonight the public. >> an i have one last question which is the last speaker brought up that other places they have a filtering system for the drinking water and we are pumping groundwater directly into our reservoirs. so do you have an answer for that? >> yes, i do. and i am biting my tongue in

response to many of the comments made because i think they impugn my professional integrity. i am not going to sit by and let that happen. in the case of groundwater, groundwater is typically not filtered at all because of the natural filtering that occurs in the aquifer. you filter out to proi primarily remove disease-causing agents, bacteria, protozoa, things like that. that is what comes out through the natural filtering process going through the hundreds of feet of groundwater. so from that bacteria logical perspective, groundwater is far superior to surface water which has animals, critters, humans in them all the time. those waters absolutely have to be filtered because we would be definitely be facing disease. we don't filter the hetch hetchy supply because it is so pure and you felt disinfection for that, but -- and we use ultraviolet

disinfection, and the sand filtration occurs in the hundreds of feet of the aquifer. >> i appreciate that this is challenging for you, but the public, we always need to be respectful of. that is part of our job as public servants and i think people expressing -- and i didn't really feel like they were impuning your integrity, but really raising questions and maybe their knowledge base is not the same as theirs and looking at different data sets, but i just feel like we should always respect the public when they come before us because they are the ones who are paying our salaries and van the right to ask tough questions even if we don't think they are coming from it with the appropriate knowledge base. >> and i totally agree with that. but to the gentleman in particular we met with for hours and hours and hours last year covering a lot of the same topics, and i thought we had provided satisfactory answers. it was difficult as if it never happened. that is frustrating for me.

>> that's the job. >> yes, it is. >> so can i recommend that we continue this item to the call of the chair? and what i am interested in is not to close this because i think there are questions that could be answered. with the questions that may come up and what i would like to do is wait. as you mentioned, mr. richie, and that you are not quite there in terms of fully activating. >> correct. >> t a that point when you are ready and before you are fully activated, that is when i would like to have another hearing to again give us an opportunity to understand this even better. >> again, i wasn't trying to be critical, but i do know so i greatly appreciate the work that the p.u.c. has put out to the community and allay their fears, but this is san francisco.

this comes with the territory. >> can i make closing comments? i am happy to continue the item to the call of the chair and continue to have this conversation at least once a year. as i said last year, i think partially we are a victim of our own branding around how pure hetch hetchy water is. and any sort of threat to that purity is not something that anyone welcomes, but it sound like a necessity to prepare for that disaster planning. and to your credit and the p.u.c. even though we can always do better outreach -- >> absolutely. >> and certainly respect our constituents that in comparison to some of the tragedies and the complete negligence happening in

other parts of the country whether it's flint, michigan, or whether it's a contamination of the water supply because of the fracking, some of the real, intense abuses that are happening, i appreciate the constant transparency that we have here in san francisco where we as a regulatory and watchdog body on the board of supervisors can constantly together with the public be monitoring the quality of our water supply and decisions that are made that impact that quality. i want to recognize and appreciate that because it's not the same in other places in the country. it is not something to take for granted. >> never. i wanted to close with that, but i am glad to make a motion to continue to the call of the chair to play that role. >> p.u.c. as an organization really does take this water

supply and the dependency on what we have now to reduce the usage with a few months ago with the ribbon cutting at the beach to build another facility to recycle water to be used for the parks and that will save so much water. i want to make sure that the public understands that we appreciate that effort. >> without objection, we will continue this to the call of the chair. and thank you, mr. richie. so mr. clerk, item three is what we are on now. >> the hearing on the city's current employment opportunities, needs, and gaps for older adults and adults with disabilities. >> i turn it over to supervisor

yee. >> supervisor: thank you very much. thank you for your patience for people that are here for this item. colleagues, today i am holding a hearing on employment situations looking at older adults and adults with disabilities. and really looking at the opportunities there are and what needs there are and what gaps there are. older adults an adults with disabilities face significant age and disability discrimination in our work force. while each group faces certain unique challenges, both groups are among the economically insecure groups in our city and country. i might give you some facts and the cost of living and many of the facts are well known to the public, but for some that don't know, the cost of living in san francisco continues to increase. most older adults are living

longer which is a good thing, but they must often survive and to work longer and retire later in life due to decreasing social security benefits and dismissing employee retirement benefits. the older adults and adults with disability population continues to grow. currently we compose of 25% of our city's population. by 2030 they will be grow to 30% of the city's population. and older adults over the age of 65 are the poorest in the city. and adults with disabilities have five times higher rates of unemployment than able-bodied individuals. over 25,000 of our city's seniors live below the poverty line on a monthly income of l