1 00:00:01,640 --> 00:00:04,040 The following content is provided under a Creative 2 00:00:04,040 --> 00:00:05,580 Commons license. 3 00:00:05,580 --> 00:00:07,880 Your support will help MIT OpenCourseWare 4 00:00:07,880 --> 00:00:12,270 continue to offer high-quality educational resources for free. 5 00:00:12,270 --> 00:00:14,870 To make a donation or view additional materials 6 00:00:14,870 --> 00:00:18,830 from hundreds of MIT courses, visit MIT OpenCourseWare 7 00:00:18,830 --> 00:00:21,620 at ocw.mit.edu. 8 00:00:21,620 --> 00:00:23,920 PROFESSOR: What we've managed through badgering 9 00:00:23,920 --> 00:00:29,320 the utilities relentlessly is to get them to agree to measure 10 00:00:29,320 --> 00:00:32,075 part or all of the high-volume gas leaks 11 00:00:32,075 --> 00:00:35,030 that they're going to fix this next year. 12 00:00:35,030 --> 00:00:37,500 But we need a method to do that. 13 00:00:37,500 --> 00:00:40,356 So one part of today is hackathon. 14 00:00:40,356 --> 00:00:44,470 And you can choose which group you want to go with. 15 00:00:44,470 --> 00:00:46,600 The part that I'm going to be working on 16 00:00:46,600 --> 00:00:52,300 is coming up with that method to quickly, easily, using utility 17 00:00:52,300 --> 00:00:55,400 common tools, measure the emissions off 18 00:00:55,400 --> 00:00:58,000 of high-volume gas leaks. 19 00:00:58,000 --> 00:01:00,680 And if we can do this-- if it's possible-- 20 00:01:00,680 --> 00:01:03,730 the state will enact the regulations 21 00:01:03,730 --> 00:01:06,120 that this must be done with every high-volume gas 22 00:01:06,120 --> 00:01:07,835 leak from now on. 23 00:01:07,835 --> 00:01:14,260 So this is an incredible chance to create a state-wide program 24 00:01:14,260 --> 00:01:17,240 to allow for feedback and transparency 25 00:01:17,240 --> 00:01:20,390 in the system to allow them to do their job much better 26 00:01:20,390 --> 00:01:24,120 in terms of reducing emissions from natural gas leaks. 27 00:01:24,120 --> 00:01:26,870 Does that somewhat make sense? 28 00:01:26,870 --> 00:01:31,050 And we've got some of the cool tools that the utilities use, 29 00:01:31,050 --> 00:01:33,300 and lots of information about how to do that. 30 00:01:33,300 --> 00:01:36,410 PROFESSOR: So who knows what a gas leak smells like? 31 00:01:36,410 --> 00:01:42,080 That's the most kind of direct sensor we have-- our noses. 32 00:01:42,080 --> 00:01:43,850 Who doesn't really have a good idea 33 00:01:43,850 --> 00:01:45,900 of what a gas leak smells like? 34 00:01:45,900 --> 00:01:46,790 OK, great. 35 00:01:46,790 --> 00:01:49,260 Well, I have these scratch and sniff cards, 36 00:01:49,260 --> 00:01:50,410 so you can find out. 37 00:01:50,410 --> 00:01:50,910 [LAUGHTER] 38 00:01:50,910 --> 00:01:53,070 And so you open these things up. 39 00:01:53,070 --> 00:01:54,770 Does anyone want to remind themselves 40 00:01:54,770 --> 00:01:56,200 of what a gas leak smells like? 41 00:01:56,200 --> 00:02:02,087 Well, this can be a little reminder [INAUDIBLE].. 42 00:02:02,087 --> 00:02:04,429 OK, so, take one, and pass them around. 43 00:02:04,429 --> 00:02:05,262 You just open it up. 44 00:02:05,262 --> 00:02:11,293 And there's a little teardrop shaped blue thing. 45 00:02:11,293 --> 00:02:13,145 And you just scratch that, and you smell it. 46 00:02:13,145 --> 00:02:13,610 AUDIENCE: Yeah. 47 00:02:13,610 --> 00:02:14,240 PROFESSOR: OK. 48 00:02:14,240 --> 00:02:15,845 So you smell that? 49 00:02:15,845 --> 00:02:18,774 OK, so when I got into this, I didn't even 50 00:02:18,774 --> 00:02:20,190 know what a gas leak smelled like. 51 00:02:20,190 --> 00:02:22,560 Like, six years ago, I had no idea. 52 00:02:22,560 --> 00:02:26,660 And then once I smelled it, it's like riding a bike. 53 00:02:26,660 --> 00:02:29,690 Now, if you haven't smelled it-- 54 00:02:29,690 --> 00:02:31,365 you're going to have that-- 55 00:02:31,365 --> 00:02:33,156 AUDIENCE: What's the chemical in the smell? 56 00:02:33,156 --> 00:02:36,530 PROFESSOR: Yeah, it's a family of compounds called mercaptans. 57 00:02:36,530 --> 00:02:41,300 They're all sulfur-based compounds. 58 00:02:41,300 --> 00:02:46,210 And our noses are just very, very sensitive to them. 59 00:02:46,210 --> 00:02:48,380 They're injected into the gas because methane 60 00:02:48,380 --> 00:02:50,540 itself is odorless. 61 00:02:50,540 --> 00:02:53,840 And it was actually mandated by federal law 62 00:02:53,840 --> 00:02:56,270 to be put in there after a huge explosion happened 63 00:02:56,270 --> 00:02:59,090 in New London, Texas, that killed hundreds of kids 64 00:02:59,090 --> 00:03:00,971 in that school. 65 00:03:00,971 --> 00:03:02,330 And no one smelled it. 66 00:03:02,330 --> 00:03:06,020 So this odorant is added at the parts per billion range. 67 00:03:06,020 --> 00:03:09,030 It's like maybe five to 10 parts per billion 68 00:03:09,030 --> 00:03:11,900 of this odorant, mercaptan. 69 00:03:11,900 --> 00:03:18,080 So we use a number of techniques to measure these gas leaks. 70 00:03:18,080 --> 00:03:20,360 As a citizen and as community science, 71 00:03:20,360 --> 00:03:27,460 your nose is really a very powerful sensor. 72 00:03:27,460 --> 00:03:31,500 The industry, what they do is they use some sniffers. 73 00:03:31,500 --> 00:03:34,620 They've been around for decades. 74 00:03:34,620 --> 00:03:37,910 One of the things they do is use this thing called 75 00:03:37,910 --> 00:03:41,120 a combustible gas indicator. 76 00:03:41,120 --> 00:03:42,890 And I'll just turn it on. 77 00:03:42,890 --> 00:03:45,275 You can hear the noise. 78 00:03:45,275 --> 00:03:46,750 That's a pump. 79 00:03:46,750 --> 00:03:54,680 And so it's pulling in air through this little hole here. 80 00:03:54,680 --> 00:03:57,540 Often there's an extension on this 81 00:03:57,540 --> 00:03:59,590 so that it can go deeper down-- 82 00:03:59,590 --> 00:04:02,210 like a meter down into the ground. 83 00:04:02,210 --> 00:04:05,020 So good thing-- right now, we're measuring 0-- 84 00:04:05,020 --> 00:04:06,340 0% gas. 85 00:04:06,340 --> 00:04:06,930 OK? 86 00:04:06,930 --> 00:04:10,130 This thing's pulling in about a half a liter per minute. 87 00:04:10,130 --> 00:04:11,576 That's the pump. 88 00:04:11,576 --> 00:04:13,990 So you see the 0 there. 89 00:04:13,990 --> 00:04:19,620 And when we go out on our drive-around on the 31st-- 90 00:04:19,620 --> 00:04:21,124 those of you who can make it-- 91 00:04:21,124 --> 00:04:26,240 if we come upon a gas leak in our very high precision, very 92 00:04:26,240 --> 00:04:27,140 sensitive sniffer-- 93 00:04:27,140 --> 00:04:28,780 this one's a little bit more coarse. 94 00:04:28,780 --> 00:04:31,475 But we can get out, and poke around, and find out, 95 00:04:31,475 --> 00:04:34,060 and pinpoint where is it under the surface 96 00:04:34,060 --> 00:04:35,780 that that gas is coming out. 97 00:04:35,780 --> 00:04:37,880 OK? 98 00:04:37,880 --> 00:04:39,970 So maybe I'll just-- 99 00:04:39,970 --> 00:04:40,750 oh, I don't know. 100 00:04:40,750 --> 00:04:41,874 I guess I'll turn this off. 101 00:04:41,874 --> 00:04:45,480 AUDIENCE: Might have to do a controlled experiment where you 102 00:04:45,480 --> 00:04:47,020 can match people against that. 103 00:04:47,020 --> 00:04:49,201 So send people and one of them. 104 00:04:49,201 --> 00:04:49,700 You know? 105 00:04:49,700 --> 00:04:50,560 PROFESSOR: Yeah. 106 00:04:50,560 --> 00:04:52,420 You know, that's a good idea. 107 00:04:52,420 --> 00:04:55,150 But I will tell you, the lower limit on this thing 108 00:04:55,150 --> 00:04:58,070 is about 500 parts per million methane. 109 00:04:58,070 --> 00:05:02,200 That's the lower detection limit on this, which is very high. 110 00:05:02,200 --> 00:05:05,890 Does anyone know what the background methane 111 00:05:05,890 --> 00:05:10,613 value is in our atmosphere in units of parts per million? 112 00:05:10,613 --> 00:05:13,771 Any wild guesses? 113 00:05:13,771 --> 00:05:15,560 AUDIENCE: Two per billion. 114 00:05:15,560 --> 00:05:17,320 PROFESSOR: Yeah, per million-- 115 00:05:17,320 --> 00:05:19,210 a little over two parts per million. 116 00:05:19,210 --> 00:05:22,649 40,000 parts per million is when it gets explosive-- 117 00:05:22,649 --> 00:05:24,485 40,000 parts per million. 118 00:05:24,485 --> 00:05:25,403 OK? 119 00:05:25,403 --> 00:05:27,239 AUDIENCE: That's 80 times [INAUDIBLE].. 120 00:05:27,239 --> 00:05:28,520 PROFESSOR: Yes. 121 00:05:28,520 --> 00:05:31,510 So there's different ranges at which this problem 122 00:05:31,510 --> 00:05:34,635 has different impacts. 123 00:05:34,635 --> 00:05:37,500 Our global value of two parts per million 124 00:05:37,500 --> 00:05:41,360 now is about something like 50% greater 125 00:05:41,360 --> 00:05:45,750 than it was in the pre-industrial condition. 126 00:05:45,750 --> 00:05:47,460 And so the greenhouse gas impacts 127 00:05:47,460 --> 00:05:52,042 of even two parts per million is very big. 128 00:05:52,042 --> 00:05:53,950 The instrumentation in our band-- 129 00:05:53,950 --> 00:05:59,710 GPS-enabled sniffer detected a series of leaks 130 00:05:59,710 --> 00:06:04,660 along about a 1/8 of a mile portion of that street. 131 00:06:04,660 --> 00:06:08,200 So we've got this graph-- and I will show you later-- 132 00:06:08,200 --> 00:06:10,030 with these peaks that come out. 133 00:06:10,030 --> 00:06:14,410 They could be plotted right out on Google Earth, OK? 134 00:06:14,410 --> 00:06:16,790 It's probable that those leaks are not 135 00:06:16,790 --> 00:06:18,240 coming from the new pipe-- 136 00:06:18,240 --> 00:06:20,080 the new West Roxbury Lateral. 137 00:06:20,080 --> 00:06:24,130 But they're probably coming from the adjacent pipes that are old 138 00:06:24,130 --> 00:06:26,290 and leaking that have already been there. 139 00:06:26,290 --> 00:06:30,820 The real lost opportunity there, in addition 140 00:06:30,820 --> 00:06:33,930 to the fact that we don't need the new pipeline, 141 00:06:33,930 --> 00:06:40,310 is that they paved brand-new paving and brand-new sidewalks. 142 00:06:40,310 --> 00:06:43,540 They didn't fix the old leaking pipelines when they 143 00:06:43,540 --> 00:06:45,040 put in this brand-new pipeline. 144 00:06:45,040 --> 00:06:48,360 And Eversource, whose territory that is, by the way, 145 00:06:48,360 --> 00:06:52,730 is a coinvestor in the West Roxbury Lateral Pipeline. 146 00:06:52,730 --> 00:06:55,819 So apparently, they just didn't care about maintaining 147 00:06:55,819 --> 00:06:56,860 their own infrastructure. 148 00:06:56,860 --> 00:06:58,668 AUDIENCE: Why wasn't it mandated? 149 00:06:58,668 --> 00:06:59,928 Why wouldn't the state-- 150 00:06:59,928 --> 00:07:00,928 AUDIENCE: Working on it. 151 00:07:00,928 --> 00:07:01,900 PROFESSOR: Yeah. 152 00:07:01,900 --> 00:07:04,930 So anyway, that's what happened. 153 00:07:04,930 --> 00:07:07,930 And so we took a picture of this. 154 00:07:07,930 --> 00:07:09,990 We have the data set. 155 00:07:09,990 --> 00:07:15,830 And what you'll see is peaks and valleys. 156 00:07:15,830 --> 00:07:17,830 There may be like 15 or 20 of them. 157 00:07:17,830 --> 00:07:20,290 But are there are 15 or 20 leaks. 158 00:07:20,290 --> 00:07:21,910 We don't know. 159 00:07:21,910 --> 00:07:24,545 And if you want to go over to the section 160 00:07:24,545 --> 00:07:29,430 that we're working at, you will be able to think about, 161 00:07:29,430 --> 00:07:32,230 is like, what is a leak? 162 00:07:32,230 --> 00:07:37,690 How many leaks are there when you get this series of spikes? 163 00:07:37,690 --> 00:07:41,080 If the spikes go like that-- tip down, and come back up again, 164 00:07:41,080 --> 00:07:43,990 and go down, is that one leak or two leaks? 165 00:07:43,990 --> 00:07:46,680 And the fact of the matter is we don't yet 166 00:07:46,680 --> 00:07:57,410 have a very universal definition of what a leak is. 167 00:07:57,410 --> 00:08:00,695 So you will help do a leak count. 168 00:08:00,695 --> 00:08:03,690 And you'll help determine, hopefully, 169 00:08:03,690 --> 00:08:06,234 what an objective leak analysis can 170 00:08:06,234 --> 00:08:11,053 be by looking at these Google Earth images of gas leaks. 171 00:08:11,053 --> 00:08:12,905 PROFESSOR: And they're gorgeous images. 172 00:08:12,905 --> 00:08:14,260 And it's just super fun. 173 00:08:14,260 --> 00:08:16,342 You feel like you're the only one who knows this information. 174 00:08:16,342 --> 00:08:16,841 It's great. 175 00:08:16,841 --> 00:08:19,620 AUDIENCE: Do you know the material of recent leak 176 00:08:19,620 --> 00:08:20,870 types and [INAUDIBLE]? 177 00:08:20,870 --> 00:08:23,560 PROFESSOR: Yeah, so the leak-prone pipe-- 178 00:08:23,560 --> 00:08:26,420 most of it is cast iron. 179 00:08:26,420 --> 00:08:29,520 And it goes back-- some pipes are over 100 years old. 180 00:08:29,520 --> 00:08:31,230 I think Audrey might have mentioned. 181 00:08:31,230 --> 00:08:32,500 There's also wrought iron. 182 00:08:32,500 --> 00:08:33,580 There's not much of that. 183 00:08:33,580 --> 00:08:36,340 But that's a very old leak-prone pipe as well. 184 00:08:36,340 --> 00:08:41,770 Bare steel is another leak-prone pipe. 185 00:08:41,770 --> 00:08:44,850 They're all being replaced-- well, when they're replaced, 186 00:08:44,850 --> 00:08:47,400 they're replaced with plastic pipe. 187 00:08:47,400 --> 00:08:55,120 And that is not as leaky because it's newer. 188 00:08:55,120 --> 00:09:01,290 AUDIENCE: This may be the wrong question, wrong time. 189 00:09:01,290 --> 00:09:05,580 Three or four years ago, there was a big issue here 190 00:09:05,580 --> 00:09:08,220 with Google Maps. 191 00:09:08,220 --> 00:09:11,690 And then Google outfitted every single car, 192 00:09:11,690 --> 00:09:16,960 and tracked and published their gas leaks all over the place. 193 00:09:16,960 --> 00:09:18,570 And rather humorously, Wellesley, 194 00:09:18,570 --> 00:09:21,650 was one of the biggest centers of the universe of gas leaks 195 00:09:21,650 --> 00:09:22,650 that they found. 196 00:09:22,650 --> 00:09:25,650 As they did all the Google drive-bys, they [INAUDIBLE].. 197 00:09:25,650 --> 00:09:29,316 They didn't know where that fit into this town [INAUDIBLE] 198 00:09:29,316 --> 00:09:30,830 technology they were using. 199 00:09:30,830 --> 00:09:34,492 But they published this, and all this, but that-- 200 00:09:34,492 --> 00:09:35,720 PROFESSOR: Yeah. 201 00:09:35,720 --> 00:09:40,370 So we published our Boston data in 2013. 202 00:09:40,370 --> 00:09:42,960 And that was all of the gas [INAUDIBLE]---- 203 00:09:42,960 --> 00:09:46,750 over 3,000 leaks in Boston. 204 00:09:46,750 --> 00:09:49,455 Very soon after that, Google partnered 205 00:09:49,455 --> 00:09:51,600 with the Environmental Defense Fund 206 00:09:51,600 --> 00:09:54,340 to basically take this nationwide. 207 00:09:54,340 --> 00:09:56,880 And so part of doing that was coming back 208 00:09:56,880 --> 00:09:58,410 to the greater Boston area. 209 00:09:58,410 --> 00:10:00,202 And they did their own map. 210 00:10:00,202 --> 00:10:02,240 They got one leak per mile in Boston. 211 00:10:02,240 --> 00:10:04,080 We got four leaks per mile in Boston. 212 00:10:04,080 --> 00:10:07,214 So that's part of figuring this out. 213 00:10:07,214 --> 00:10:10,660 So almost everything that's under the streets and sidewalks 214 00:10:10,660 --> 00:10:14,210 in Boston, Somerville, Cambridge, Newton, Brookline, 215 00:10:14,210 --> 00:10:17,930 is just about a half a pound per square inch 216 00:10:17,930 --> 00:10:21,940 of pressure under the streets and sidewalks. 217 00:10:21,940 --> 00:10:22,850 But it's like a tree. 218 00:10:22,850 --> 00:10:24,170 You have these trunk lines. 219 00:10:24,170 --> 00:10:25,855 And you have the big branches. 220 00:10:25,855 --> 00:10:28,080 And then you have the little twigs. 221 00:10:28,080 --> 00:10:30,860 So you have these intermediate branches running down 222 00:10:30,860 --> 00:10:32,710 Route 9 that-- 223 00:10:32,710 --> 00:10:34,960 it's either 22 or it's 40 psi. 224 00:10:34,960 --> 00:10:36,182 And it's leaking. 225 00:10:38,780 --> 00:10:41,100 PROFESSOR: So today, you'll either 226 00:10:41,100 --> 00:10:45,002 decide to work on visualizing the data, looking at the data, 227 00:10:45,002 --> 00:10:50,432 or working on figuring out how to measure the high-volume gas 228 00:10:50,432 --> 00:10:50,932 leaks. 229 00:10:50,932 --> 00:10:53,146 So you'll sort of self-select into whatever group 230 00:10:53,146 --> 00:10:54,030 you want to do. 231 00:10:54,030 --> 00:10:56,042 Is there a question back here? 232 00:10:56,042 --> 00:10:57,960 AUDIENCE: Just a basic question. 233 00:10:57,960 --> 00:11:00,717 Do you know how deep these lines were buried? 234 00:11:00,717 --> 00:11:02,610 PROFESSOR: Yeah, it's variable. 235 00:11:02,610 --> 00:11:06,190 About three feet is generally how deep they are. 236 00:11:06,190 --> 00:11:10,590 They put them deep enough that it 237 00:11:10,590 --> 00:11:15,534 will reduce the frequency with which they freeze. 238 00:11:15,534 --> 00:11:18,900 But in frost conditions-- deep freezes-- 239 00:11:18,900 --> 00:11:22,580 you can get mechanical disturbance due to frost. 240 00:11:22,580 --> 00:11:26,922 And you can have broken mains, and things like that. 241 00:11:26,922 --> 00:11:29,500 But anything's possible. 242 00:11:29,500 --> 00:11:31,000 You know, one thing I've learned is 243 00:11:31,000 --> 00:11:37,155 that I mean, for the most part, gas lines run 244 00:11:37,155 --> 00:11:40,770 along the same axis as a street. 245 00:11:40,770 --> 00:11:43,620 But they'll run diagonal. 246 00:11:43,620 --> 00:11:46,257 And they'll be on both sides of the street. 247 00:11:46,257 --> 00:11:47,590 And they'll run under sidewalks. 248 00:11:47,590 --> 00:11:49,600 And they'll go this way and that. 249 00:11:49,600 --> 00:11:54,390 And I can just see any configuration. 250 00:11:54,390 --> 00:11:56,496 There's a legacy effect of this. 251 00:11:56,496 --> 00:11:58,530 It can be like spaghetti down there. 252 00:11:58,530 --> 00:12:02,130 AUDIENCE: Are there maps of the existing pipeline? 253 00:12:02,130 --> 00:12:04,190 PROFESSOR: Yes, and no. 254 00:12:04,190 --> 00:12:08,100 There are public documents that show 255 00:12:08,100 --> 00:12:13,660 the operating pressure for that natural grid's service area. 256 00:12:13,660 --> 00:12:19,020 And I can share that graph. 257 00:12:19,020 --> 00:12:21,990 But there's not the detailed information 258 00:12:21,990 --> 00:12:26,470 on those maps that tell you the diameter, the age, 259 00:12:26,470 --> 00:12:28,780 and the material of all of the pipes. 260 00:12:28,780 --> 00:12:33,940 There are selected parts that we know of. 261 00:12:33,940 --> 00:12:38,202 I mean, some of these have, obviously, these maps. 262 00:12:38,202 --> 00:12:40,470 But they're not public. 263 00:12:40,470 --> 00:12:42,453 Only some have been made public. 264 00:12:42,453 --> 00:12:44,191 And it's very selective. 265 00:12:44,191 --> 00:12:47,946 PROFESSOR: So you can look at how to visualize the data, 266 00:12:47,946 --> 00:12:52,905 and get to figure out how many leaks there are in Chelsea-- 267 00:12:52,905 --> 00:12:54,620 how exciting-- and actually see where 268 00:12:54,620 --> 00:13:01,160 the leaks are, or figure out how to measure the emissions.