WEBVTT 00:00:01.640 --> 00:00:04.040 The following content is provided under a Creative 00:00:04.040 --> 00:00:05.580 Commons license. 00:00:05.580 --> 00:00:07.880 Your support will help MIT OpenCourseWare 00:00:07.880 --> 00:00:12.270 continue to offer high quality educational resources for free. 00:00:12.270 --> 00:00:14.870 To make a donation or view additional materials 00:00:14.870 --> 00:00:18.830 from hundreds of MIT courses, visit MIT OpenCourseWare 00:00:18.830 --> 00:00:20.000 at ocw.mit.edu. 00:00:22.940 --> 00:00:26.090 NATHAN PHILLIPS: Introductions, Audrey Schulman. 00:00:26.090 --> 00:00:26.990 AUDREY SCHULMAN: Hey. 00:00:26.990 --> 00:00:28.910 NATHAN PHILLIPS: HEET, Home Energy Efficiency Team. 00:00:28.910 --> 00:00:29.870 I'm Nathan Phillips. 00:00:29.870 --> 00:00:32.330 I teach at Boston University. 00:00:32.330 --> 00:00:36.440 And the previous speakers, I think, 00:00:36.440 --> 00:00:40.010 really talk to how the environmental problems 00:00:40.010 --> 00:00:44.360 that we have are either invisible or very hard 00:00:44.360 --> 00:00:45.120 to grasp. 00:00:45.120 --> 00:00:47.330 So being able to see these things with evidence, 00:00:47.330 --> 00:00:51.770 photographs or having simple and precise metrics 00:00:51.770 --> 00:00:56.360 to understand the magnitude of our climate impacts 00:00:56.360 --> 00:00:57.030 is important. 00:00:57.030 --> 00:00:59.900 So this is very much in line with this. 00:00:59.900 --> 00:01:03.020 And so some of you here have been with us 00:01:03.020 --> 00:01:07.160 from the start, when we met here a couple of weeks ago. 00:01:07.160 --> 00:01:10.440 Some of you came in midstream. 00:01:10.440 --> 00:01:15.020 So we laid out this problem about the methane gas leaks 00:01:15.020 --> 00:01:17.090 from the natural gas pipeline infrastructure 00:01:17.090 --> 00:01:20.000 under Boston, Cambridge, Somerville, Eastern United 00:01:20.000 --> 00:01:21.650 States. 00:01:21.650 --> 00:01:24.590 Then we talked about solutions. 00:01:24.590 --> 00:01:28.880 We had a hackathon about a week and a half ago or a week ago. 00:01:28.880 --> 00:01:32.390 And then, yesterday, Audrey and I, 00:01:32.390 --> 00:01:35.480 and some of the people in this room, hopped in a van, 00:01:35.480 --> 00:01:38.420 and we started sniffing these gas leaks 00:01:38.420 --> 00:01:40.970 and mapping them on Google Earth. 00:01:40.970 --> 00:01:44.180 And so we just wanted to share with you-- 00:01:44.180 --> 00:01:46.490 how many people were actually in the van with us? 00:01:46.490 --> 00:01:49.730 So a good chunk of us here. 00:01:49.730 --> 00:01:51.830 So this was us yesterday. 00:01:51.830 --> 00:01:57.019 And this is a combined map here of both of the trips 00:01:57.019 --> 00:01:57.560 that we took. 00:01:57.560 --> 00:02:02.060 So the first van load, we had a full van of 12 people, 00:02:02.060 --> 00:02:04.850 and we drove from here to Somerville and back. 00:02:04.850 --> 00:02:07.110 And then we pretty much did the same thing 00:02:07.110 --> 00:02:09.710 with a little slight variation in the second trip. 00:02:09.710 --> 00:02:14.450 So let's see-- so that's where we are right now, 00:02:14.450 --> 00:02:15.606 is that correct, Audrey? 00:02:15.606 --> 00:02:17.480 AUDREY SCHULMAN: Yeah, and an important thing 00:02:17.480 --> 00:02:19.390 to know is that there's a baseline about two 00:02:19.390 --> 00:02:23.285 parts per million in this, so that the wall, everywhere, 00:02:23.285 --> 00:02:25.035 is just a baseline of methane that exists. 00:02:28.364 --> 00:02:30.280 That used to be lower-- 00:02:30.280 --> 00:02:32.200 NATHAN PHILLIPS: No, let's share this, please. 00:02:32.200 --> 00:02:34.020 But actually please-- 00:02:34.020 --> 00:02:36.620 AUDREY SCHULMAN: Sorry? 00:02:36.620 --> 00:02:39.733 AUDIENCE: So it's Mercer Street, that's the methane leak? 00:02:39.733 --> 00:02:43.290 AUDREY SCHULMAN: Yeah, so there's a big league 00:02:43.290 --> 00:02:47.100 somewhere here, right in front of the most iconic part of MIT. 00:02:47.100 --> 00:02:48.420 AUDIENCE: [INAUDIBLE] 00:02:48.420 --> 00:02:50.170 AUDREY SCHULMAN: Oh sorry, you want me to? 00:02:50.170 --> 00:02:51.503 NATHAN PHILLIPS: Oh, I'll do it. 00:02:53.190 --> 00:02:56.920 AUDREY SCHULMAN: But the wall here that you see of everywhere 00:02:56.920 --> 00:02:58.110 where we drove? 00:02:58.110 --> 00:03:01.140 That's sort of just the parts per million of methane 00:03:01.140 --> 00:03:02.670 that's just background noise. 00:03:05.190 --> 00:03:08.085 And the big spikes are where there were leaks. 00:03:10.950 --> 00:03:17.130 So and what's interesting is, we did a US survey of Cambridge 00:03:17.130 --> 00:03:21.840 and Somerville two years ago, and there was a leak here. 00:03:21.840 --> 00:03:23.910 So there still is. 00:03:23.910 --> 00:03:26.150 It's nice to know. 00:03:26.150 --> 00:03:29.650 What do you want to say? 00:03:29.650 --> 00:03:33.780 NATHAN PHILLIPS: Well, how about we go to the area, 00:03:33.780 --> 00:03:35.840 where it was it, Prince Street in Somerville? 00:03:35.840 --> 00:03:36.870 AUDREY SCHULMAN: Pearl Street. 00:03:36.870 --> 00:03:38.120 NATHAN PHILLIPS: Pearl Street. 00:03:38.120 --> 00:03:39.320 Let's take a look at. 00:03:39.320 --> 00:03:43.170 AUDREY SCHULMAN: So here's us going by Kendall. 00:03:50.580 --> 00:03:52.050 And then back-- 00:03:54.942 --> 00:03:55.900 I'm having a prankster. 00:03:55.900 --> 00:03:57.733 NATHAN PHILLIPS: Thanks for driving, Audrey. 00:03:57.733 --> 00:04:00.172 I'm not good at Mac. 00:04:00.172 --> 00:04:01.380 AUDREY SCHULMAN: OK, yeah no. 00:04:01.380 --> 00:04:04.290 Mac is my language. 00:04:04.290 --> 00:04:10.430 So that's Pearl Street there, the big mountains. 00:04:10.430 --> 00:04:11.420 NATHAN PHILLIPS: Now. 00:04:11.420 --> 00:04:13.770 These are all National Grid, right? 00:04:13.770 --> 00:04:17.160 AUDREY SCHULMAN: Yeah so the difference between Eversource 00:04:17.160 --> 00:04:21.279 and National Grid is this train track right here. 00:04:21.279 --> 00:04:25.320 So this is Eversource down here, this is National Grid up there. 00:04:25.320 --> 00:04:26.970 And we don't know what's going on, 00:04:26.970 --> 00:04:30.060 whether there's a difference in its operating 00:04:30.060 --> 00:04:33.420 pressure of the pipes, or age of the pipes, 00:04:33.420 --> 00:04:36.840 material of the pipes, or difference in how the two 00:04:36.840 --> 00:04:39.200 companies deal with leaks. 00:04:39.200 --> 00:04:42.660 But you know, two years ago, when we did the survey, 00:04:42.660 --> 00:04:43.890 there were-- 00:04:43.890 --> 00:04:47.660 you know, this area of National Grid's was the Swiss Alps 00:04:47.660 --> 00:04:49.710 of Somerville. 00:04:49.710 --> 00:04:51.897 And it seems to still be that way. 00:04:51.897 --> 00:04:53.980 NATHAN PHILLIPS: So just a couple of observations. 00:04:53.980 --> 00:04:57.870 And please, you were there, so offer your own observations 00:04:57.870 --> 00:05:00.240 or questions about this because this 00:05:00.240 --> 00:05:02.030 is a very rich data set there. 00:05:02.030 --> 00:05:04.770 It raises lots of questions to me. 00:05:04.770 --> 00:05:07.650 So you can see here, there's actually a couple traces, 00:05:07.650 --> 00:05:08.360 right? 00:05:08.360 --> 00:05:09.960 Here there's two traces. 00:05:09.960 --> 00:05:12.540 We drove it two times in two trips. 00:05:12.540 --> 00:05:15.360 You see that there some variation each time. 00:05:15.360 --> 00:05:18.030 And we talked about the vagaries of wind, 00:05:18.030 --> 00:05:20.070 and you know, if the wind's blowing harder 00:05:20.070 --> 00:05:21.600 in one direction one time, you'll 00:05:21.600 --> 00:05:25.060 get something slightly different. 00:05:25.060 --> 00:05:26.030 So is this a leak? 00:05:26.030 --> 00:05:27.690 Is it the same thing as this? 00:05:27.690 --> 00:05:30.030 What do we actually-- 00:05:30.030 --> 00:05:33.820 how do we take continuous data like this 00:05:33.820 --> 00:05:38.640 and objectify it in terms of, well, there is a leak. 00:05:38.640 --> 00:05:41.520 It's difficult. It's tricky to do. 00:05:41.520 --> 00:05:43.800 And you know there are pipeline leaks. 00:05:43.800 --> 00:05:46.140 There are holes in pipes. 00:05:46.140 --> 00:05:48.210 And then there are methane leaks. 00:05:48.210 --> 00:05:50.370 And they come out of the ground. 00:05:50.370 --> 00:05:57.380 So even the terminology we use is not quite fully worked out. 00:05:57.380 --> 00:05:58.260 There's a lot here. 00:06:01.500 --> 00:06:02.730 Some of the things that-- 00:06:02.730 --> 00:06:06.660 so in terms of, at one level, at a very broad level, 00:06:06.660 --> 00:06:08.650 Pearl Street is a mess. 00:06:08.650 --> 00:06:12.450 It's leaking methane all along that street. 00:06:12.450 --> 00:06:15.270 When we get to policy, state policy 00:06:15.270 --> 00:06:17.280 makers and the utilities, and the regulators 00:06:17.280 --> 00:06:20.250 want to know, well, how many leaks are there? 00:06:20.250 --> 00:06:22.912 Because that determines, like, how many 00:06:22.912 --> 00:06:24.870 crews that are going to go out, and how they're 00:06:24.870 --> 00:06:26.828 going to schedule, and how they're going to get 00:06:26.828 --> 00:06:31.200 reimbursed, or repaid for a fixed number of things 00:06:31.200 --> 00:06:32.280 that they do. 00:06:32.280 --> 00:06:36.540 So this is a complicated kind of policy science 00:06:36.540 --> 00:06:39.772 type of framework. 00:06:39.772 --> 00:06:41.230 Do you have any other observations? 00:06:41.230 --> 00:06:42.980 AUDREY SCHULMAN: Yeah, I want to point out 00:06:42.980 --> 00:06:45.630 one thing in terms of policy. 00:06:45.630 --> 00:06:49.330 This area right here is where they'd 00:06:49.330 --> 00:06:53.340 taken out the cast iron main that is quite old 00:06:53.340 --> 00:06:54.690 and put in plastic. 00:06:54.690 --> 00:06:56.567 And we could see-- 00:06:56.567 --> 00:06:57.650 I think that that's right. 00:06:57.650 --> 00:06:58.070 NATHAN PHILLIPS: Franklin, is that Franklin? 00:06:58.070 --> 00:06:59.861 AUDREY SCHULMAN: Yeah I'm assuming that is. 00:06:59.861 --> 00:07:01.110 We can go in closer. 00:07:01.110 --> 00:07:03.390 But there was one part where we saw 00:07:03.390 --> 00:07:05.190 that they've taken out the old gas main 00:07:05.190 --> 00:07:07.650 and put in a new, better one. 00:07:07.650 --> 00:07:09.179 And I'm betting it's that area. 00:07:09.179 --> 00:07:10.887 AUDIENCE: So, were you surprised by this? 00:07:15.110 --> 00:07:17.750 NATHAN PHILLIPS: Not any more. 00:07:17.750 --> 00:07:24.750 So when we published our first publication in late 2012, 00:07:24.750 --> 00:07:30.120 early 2013, it basically made it a problem 00:07:30.120 --> 00:07:35.790 that was well known to the utilities known to, at least, 00:07:35.790 --> 00:07:40.310 I don't want to say everyone, but people who saw the paper, 00:07:40.310 --> 00:07:43.760 and members of the public that read some of the press that 00:07:43.760 --> 00:07:45.360 came out about it. 00:07:45.360 --> 00:07:50.930 So that was unexpected to the utilities. 00:07:50.930 --> 00:07:52.680 And it kind of knocked them back. 00:07:52.680 --> 00:07:55.990 It's like, oh, we have data that's coming out. 00:07:55.990 --> 00:07:59.210 So they didn't control the data. 00:07:59.210 --> 00:08:04.920 And so just by virtue of having data out there, 00:08:04.920 --> 00:08:08.960 it has basically, kind of say, balanced 00:08:08.960 --> 00:08:14.000 the power a little bit, or a lot, to get change to happen 00:08:14.000 --> 00:08:17.136 and policy to be made. 00:08:17.136 --> 00:08:17.890 Is this Franklin? 00:08:17.890 --> 00:08:18.930 AUDREY SCHULMAN: Yeah, I don't know. 00:08:18.930 --> 00:08:19.555 I couldn't see. 00:08:19.555 --> 00:08:22.960 I tried to figure it out. 00:08:22.960 --> 00:08:24.520 Anybody know Somerville really well? 00:08:24.520 --> 00:08:26.187 What's the street parallel to Roland? 00:08:26.187 --> 00:08:28.520 AUDIENCE: Can you assign these leaks to a specific pipe? 00:08:36.870 --> 00:08:42.250 What's the spatial resolution of assigning a spike to the--? 00:08:42.250 --> 00:08:47.860 NATHAN PHILLIPS: Yeah, so when we go by here, 00:08:47.860 --> 00:08:51.850 any one of these kind of discrete spikes, the window 00:08:51.850 --> 00:08:55.120 in which leaks may be coming out is probably 00:08:55.120 --> 00:08:57.715 on the border of a few tens of meters. 00:09:00.940 --> 00:09:05.740 And that's dictated both by the spatial source. 00:09:05.740 --> 00:09:08.090 It may-- even one pipeline leak, like I said, 00:09:08.090 --> 00:09:10.270 could be coming up in various locations, 00:09:10.270 --> 00:09:12.350 and then the wind may be blowing it around. 00:09:12.350 --> 00:09:14.170 So that's what this is allowing us to do. 00:09:14.170 --> 00:09:19.750 But then streets sometimes have multiple pipelines running down 00:09:19.750 --> 00:09:20.440 the same street. 00:09:20.440 --> 00:09:25.530 Sometimes they only have one main running down the street. 00:09:25.530 --> 00:09:29.260 So you have to go in a little more carefully 00:09:29.260 --> 00:09:33.370 and use, basically, probes that check 00:09:33.370 --> 00:09:36.760 what's coming out of the ground to actually pinpoint 00:09:36.760 --> 00:09:39.520 the actual pipe and where it's leaking. 00:09:39.520 --> 00:09:41.890 So this doesn't do this. 00:09:41.890 --> 00:09:45.640 This basically just says, Pearl Street is a mess, 00:09:45.640 --> 00:09:47.530 and it's got a lot of leak problems. 00:09:47.530 --> 00:09:52.265 And it requires a walking survey to go back and to be more-- 00:09:52.265 --> 00:09:54.640 AUDIENCE: Have you done some very basic signal processing 00:09:54.640 --> 00:09:55.140 on it? 00:09:57.610 --> 00:10:00.850 So run a low pass filter just to get rid 00:10:00.850 --> 00:10:03.810 of the small frequencies? 00:10:03.810 --> 00:10:07.390 NATHAN PHILLIPS: No, and I think that's the type of analysis 00:10:07.390 --> 00:10:10.120 that would be fabulous to do here. 00:10:10.120 --> 00:10:12.027 AUDREY SCHULMAN: Know anybody who can help? 00:10:12.027 --> 00:10:13.360 AUDIENCE: I can take it farther. 00:10:18.404 --> 00:10:19.320 NATHAN PHILLIPS: Yeah? 00:10:19.320 --> 00:10:30.190 AUDIENCE: [INAUDIBLE] You can detect the pattern that 00:10:30.190 --> 00:10:32.004 reflects the leak-- 00:10:32.004 --> 00:10:32.920 NATHAN PHILLIPS: Yeah. 00:10:32.920 --> 00:10:40.540 AUDIENCE: [INAUDIBLE] 00:10:40.540 --> 00:10:42.460 NATHAN PHILLIPS: So here's one thing 00:10:42.460 --> 00:10:46.020 that I think we all Audrey and I have 00:10:46.020 --> 00:10:51.280 been trying to make progress on is, how do you take this data 00:10:51.280 --> 00:10:56.070 and use it to help us start to quantify how much is coming 00:10:56.070 --> 00:10:56.830 out? 00:10:56.830 --> 00:11:00.050 And that's also a very difficult thing because, first of all, 00:11:00.050 --> 00:11:02.730 you're looking at this, and it implies something quantitative, 00:11:02.730 --> 00:11:04.480 but you don't see any numbers here, right? 00:11:04.480 --> 00:11:08.290 So probably you're wondering, well, how big are these spikes? 00:11:08.290 --> 00:11:11.260 And actually, you know, this data just came out, 00:11:11.260 --> 00:11:13.720 so I haven't been able to process, 00:11:13.720 --> 00:11:17.490 but we know that this is sitting right around 2.0, 00:11:17.490 --> 00:11:21.040 maybe 1.95, I forget what our baseline is. 00:11:21.040 --> 00:11:22.154 It's in the KML file. 00:11:22.154 --> 00:11:23.070 We could open that up. 00:11:23.070 --> 00:11:24.010 It's just a text file. 00:11:24.010 --> 00:11:27.040 It tells you what we set the baseline at-- 00:11:27.040 --> 00:11:30.100 that baseline can shift from day to day, by the way. 00:11:30.100 --> 00:11:31.010 What is this value? 00:11:31.010 --> 00:11:32.140 I'll have to find it out. 00:11:32.140 --> 00:11:33.520 It would be great to have-- 00:11:33.520 --> 00:11:36.340 we were talking about something that some students could 00:11:36.340 --> 00:11:39.614 do is come up with a processor that just basically plops 00:11:39.614 --> 00:11:40.280 numbers on here. 00:11:40.280 --> 00:11:41.560 So we could see that. 00:11:41.560 --> 00:11:43.480 What was the concentration? 00:11:43.480 --> 00:11:46.450 If we go, you know, just for setting the scale, 00:11:46.450 --> 00:11:49.480 I remember, and the four of us in the van 00:11:49.480 --> 00:11:53.890 for the second round, we went to Sullivan Square. 00:11:53.890 --> 00:11:56.530 And I think, what was the top read we got there? 00:11:56.530 --> 00:11:57.519 We were reading it off. 00:11:57.519 --> 00:11:59.310 AUDREY SCHULMAN: It was like 90, wasn't it? 00:11:59.310 --> 00:12:00.850 Wasn't it something really ridiculous? 00:12:00.850 --> 00:12:02.308 I've never seen that number before. 00:12:02.308 --> 00:12:06.250 NATHAN PHILLIPS: I recall up around 67 or 70 parts 00:12:06.250 --> 00:12:08.270 per million in the air. 00:12:08.270 --> 00:12:12.017 AUDREY SCHULMAN: So it's that spike right there, see? 00:12:12.017 --> 00:12:14.350 NATHAN PHILLIPS: So there's something really interesting 00:12:14.350 --> 00:12:14.990 about this. 00:12:14.990 --> 00:12:16.720 So we can put numbers on that. 00:12:16.720 --> 00:12:19.030 We have done that, and it's just, 00:12:19.030 --> 00:12:22.150 we haven't had a chance to do it. 00:12:22.150 --> 00:12:27.430 But actually this is really a very interesting issue 00:12:27.430 --> 00:12:29.080 of data display. 00:12:29.080 --> 00:12:31.510 I'd be interested-- who's that data person that, 00:12:31.510 --> 00:12:33.964 the display of data-- 00:12:33.964 --> 00:12:34.880 AUDIENCE: [INAUDIBLE]. 00:12:34.880 --> 00:12:37.213 NATHAN PHILLIPS: Yeah, I'd be interested to hear someone 00:12:37.213 --> 00:12:39.340 like that's take because there was a utility 00:12:39.340 --> 00:12:42.520 person from National Grid that basically called us out 00:12:42.520 --> 00:12:44.480 on this. 00:12:44.480 --> 00:12:46.480 And the point this person made was, 00:12:46.480 --> 00:12:49.650 it's like, you're scaring people by doing this. 00:12:49.650 --> 00:12:52.780 You're taking-- it's an apples and oranges thing. 00:12:52.780 --> 00:12:55.000 You're putting some data. 00:12:55.000 --> 00:12:58.690 And all of the houses, and all of us, are, like, down here, 00:12:58.690 --> 00:13:01.750 and you're creating these things that are just making it 00:13:01.750 --> 00:13:05.110 look like the world is ending. 00:13:05.110 --> 00:13:08.920 And I kind of get that, at one level, 00:13:08.920 --> 00:13:13.690 is that this is really apples to oranges type of thing 00:13:13.690 --> 00:13:18.340 because we're conflating PPM values parts, per million 00:13:18.340 --> 00:13:21.480 with meters, or space. 00:13:21.480 --> 00:13:23.390 And they are two different beasts, 00:13:23.390 --> 00:13:25.090 and we're like putting them together. 00:13:25.090 --> 00:13:26.320 But I will say this. 00:13:26.320 --> 00:13:27.790 As a scientist, the first thing I 00:13:27.790 --> 00:13:31.780 was trained as a freshman was, if you have data, 00:13:31.780 --> 00:13:33.850 and you're going to graph it, use 00:13:33.850 --> 00:13:37.870 the space available to fit your data, you know, 00:13:37.870 --> 00:13:39.080 and maximize that space. 00:13:39.080 --> 00:13:41.420 So when I want to plot this, I want 00:13:41.420 --> 00:13:44.800 to make it visible as best I can. 00:13:44.800 --> 00:13:46.969 AUDIENCE: [INAUDIBLE] I think it might 00:13:46.969 --> 00:13:48.552 be useful to come up with a unit, that 00:13:48.552 --> 00:13:53.870 is understandable as a measurement unit. 00:13:53.870 --> 00:13:56.100 It could be anything. 00:13:56.100 --> 00:13:58.970 And I will not mention that word, 00:13:58.970 --> 00:14:03.170 but stuff that comes out of us as-- 00:14:03.170 --> 00:14:06.900 I say, you know, what is the concept? 00:14:06.900 --> 00:14:09.046 So something that says-- 00:14:11.070 --> 00:14:12.460 AUDREY SCHULMAN: Nathan's idea is 00:14:12.460 --> 00:14:15.770 to sort of take just sort of some number that 00:14:15.770 --> 00:14:18.440 covers this whole area for this leak, 00:14:18.440 --> 00:14:21.315 so that it adds up the whole area underneath that. 00:14:21.315 --> 00:14:22.830 AUDIENCE: So you can bin that. 00:14:22.830 --> 00:14:27.050 But what I'm saying, as an understandable measure, 00:14:27.050 --> 00:14:32.930 something that says the height is measured in terms of a unit 00:14:32.930 --> 00:14:38.390 that we all recognize as a relevant unit for gas. 00:14:38.390 --> 00:14:42.310 [INAUDIBLE] 00:14:42.310 --> 00:14:45.830 AUDIENCE: But you could be able to reverse model it, right? 00:14:45.830 --> 00:14:47.980 So put it in an atmospheric model 00:14:47.980 --> 00:14:51.650 and say the concentration at three feet above the ground 00:14:51.650 --> 00:14:54.030 is X. What's the leak rate have to be 00:14:54.030 --> 00:14:58.430 to get that concentration here in this pattern? 00:14:58.430 --> 00:15:00.827 And figure out, how much they're actually emitting, 00:15:00.827 --> 00:15:03.630 and then you have a number that is at least in terms 00:15:03.630 --> 00:15:04.977 of their dollars, right? 00:15:04.977 --> 00:15:07.060 AUDREY SCHULMAN: But it's hard to do that somewhat 00:15:07.060 --> 00:15:08.776 because the wind will be going by. 00:15:08.776 --> 00:15:10.317 NATHAN PHILLIPS: Right, but the wind, 00:15:10.317 --> 00:15:12.275 so you do it on a couple of days, and you have, 00:15:12.275 --> 00:15:15.430 you put in the wind data to your model. 00:15:15.430 --> 00:15:19.390 And then your model says, this methane at this first rate, 00:15:19.390 --> 00:15:21.680 it back-calculates-- 00:15:21.680 --> 00:15:24.800 from your concentration, back-calculates an emission 00:15:24.800 --> 00:15:26.850 based on the weather data as well. 00:15:26.850 --> 00:15:29.675 Normalize that over multiple days of testing, 00:15:29.675 --> 00:15:32.780 and then you say, this roughly equates to X emission. 00:15:32.780 --> 00:15:35.600 And there are research groups that 00:15:35.600 --> 00:15:38.100 are trying to do exactly that. 00:15:38.100 --> 00:15:41.600 So what you have are the turbulence experts, the people 00:15:41.600 --> 00:15:44.990 that study micro meteorology, and boundary layers, 00:15:44.990 --> 00:15:46.130 and I'm not that person. 00:15:46.130 --> 00:15:47.465 I know that person. 00:15:47.465 --> 00:15:49.410 AUDREY SCHULMAN: I don't even know dispersion. 00:15:49.410 --> 00:15:54.070 NATHAN PHILLIPS: But these are the future areas to take this 00:15:54.070 --> 00:15:55.820 and to try to model. 00:15:55.820 --> 00:15:57.861 AUDIENCE: See, I'm wondering against whether this 00:15:57.861 --> 00:16:00.110 is a physics problem or a statistics problem. 00:16:00.110 --> 00:16:01.820 AUDREY SCHULMAN: Yes. 00:16:01.820 --> 00:16:04.016 NATHAN PHILLIPS: Yes, it is. 00:16:04.016 --> 00:16:06.140 AUDIENCE: Because I feel like some of these things, 00:16:06.140 --> 00:16:09.020 you could get very complex physics because 00:16:09.020 --> 00:16:11.710 of the nature of the scales at which you 00:16:11.710 --> 00:16:16.450 were trying to model this thing, or run a machine learning 00:16:16.450 --> 00:16:19.050 algorithm against it and see what is your best predictor. 00:16:19.050 --> 00:16:20.716 NATHAN PHILLIPS: And I just want to make 00:16:20.716 --> 00:16:23.300 a really quick point here is, like here's 00:16:23.300 --> 00:16:25.160 one of these spikes, right? 00:16:25.160 --> 00:16:29.030 This value, let's say it's 10 PPM, that's 00:16:29.030 --> 00:16:34.490 important on its own because, for example, air quality is 00:16:34.490 --> 00:16:37.340 related to concentration of methane in the air. 00:16:37.340 --> 00:16:40.450 It's a precursor to ozone. 00:16:40.450 --> 00:16:44.480 The area under this curve, we think, 00:16:44.480 --> 00:16:49.490 may be a correlant for how much is coming out. 00:16:49.490 --> 00:16:51.820 And that becomes an energy point, 00:16:51.820 --> 00:16:57.180 or an equivalent carbon unit is this area under the curve. 00:16:57.180 --> 00:16:59.660 But you know, these need to be validated. 00:16:59.660 --> 00:17:01.640 Everyone in the class now, I think, 00:17:01.640 --> 00:17:05.599 I sent the email out, you have the KML file. 00:17:05.599 --> 00:17:07.829 You have this data. 00:17:07.829 --> 00:17:11.609 You have an ASCII data file, which generated this. 00:17:11.609 --> 00:17:14.819 You'd have to-- the columns are actually 00:17:14.819 --> 00:17:17.467 pretty easy understand, for the most part. 00:17:17.467 --> 00:17:18.550 But you are now empowered. 00:17:18.550 --> 00:17:19.633 This is community science. 00:17:19.633 --> 00:17:22.400 And you can explore, and analyze, 00:17:22.400 --> 00:17:24.180 and run with this data. 00:17:24.180 --> 00:17:27.826 AUDIENCE: I could forward it to everybody who's signed in. 00:17:27.826 --> 00:17:29.490 Nathan, I have an unrelated question 00:17:29.490 --> 00:17:29.740 that I'm really curious about. 00:17:29.740 --> 00:17:31.823 Have you ever driven near a cow farm, a beef farm? 00:17:36.620 --> 00:17:40.280 NATHAN PHILLIPS: So the one that sticks out in my mind is 00:17:40.280 --> 00:17:46.850 driving from San Francisco to LA on Interstate 5 getting close 00:17:46.850 --> 00:17:52.550 to the Southern Mountains, giant feed lot right next to I-5, 00:17:52.550 --> 00:17:55.730 and very flat baseline, and then, you know, 00:17:55.730 --> 00:17:58.910 this very sloping increase as we passed by that feed lot 00:17:58.910 --> 00:18:02.390 to about, I think it was 2 and 1/2, 00:18:02.390 --> 00:18:06.610 3 parts per million of methane going from below 2-- 00:18:06.610 --> 00:18:09.382 but the thing there, it's not like this spike 00:18:09.382 --> 00:18:10.340 like we're seeing here. 00:18:10.340 --> 00:18:12.240 It's just this blob. 00:18:12.240 --> 00:18:13.670 It's a very extended blob. 00:18:13.670 --> 00:18:15.920 AUDIENCE: That's why I think integration is important. 00:18:15.920 --> 00:18:21.060 So you want to do not just a spike but a spike times area. 00:18:24.060 --> 00:18:26.580 AUDIENCE: Which an air dispersion model 00:18:26.580 --> 00:18:30.021 would essentially-- would do. 00:18:30.021 --> 00:18:32.020 AUDREY SCHULMAN: So we're going to need somebody 00:18:32.020 --> 00:18:33.368 to help us with this. 00:18:33.368 --> 00:18:35.243 NATHAN PHILLIPS: Yeah, these are great ideas. 00:18:35.243 --> 00:18:35.743 Question? 00:18:35.743 --> 00:18:38.630 AUDIENCE: I just wanted to know, can you 00:18:38.630 --> 00:18:41.590 get ahold of this device? 00:18:41.590 --> 00:18:43.950 How much does it cost? 00:18:43.950 --> 00:18:46.190 NATHAN PHILLIPS: The Picarro analyzer that we used-- 00:18:46.190 --> 00:18:51.340 and that's now six, seven years old, that was about $60,000. 00:18:51.340 --> 00:18:54.660 And the manufacturer, it's kind of like, 00:18:54.660 --> 00:18:55.950 they don't have a price list. 00:18:55.950 --> 00:18:57.510 They're like, call us and let's talk. 00:18:57.510 --> 00:18:59.010 AUDIENCE: So that's just for the box 00:18:59.010 --> 00:19:01.714 with the mirrors and the laser. 00:19:01.714 --> 00:19:02.880 NATHAN PHILLIPS: Yeah, yeah. 00:19:02.880 --> 00:19:04.035 So you know, it's not really-- 00:19:04.035 --> 00:19:06.451 AUDIENCE: This is the kind of stuff we have to [INAUDIBLE] 00:19:06.451 --> 00:19:07.380 NATHAN PHILLIPS: Yeah. 00:19:07.380 --> 00:19:10.260 But, what I will say is that, or maybe 00:19:10.260 --> 00:19:13.785 Audrey wants to talk about the hand held? 00:19:13.785 --> 00:19:15.802 The Sierra Club HEET thing. 00:19:15.802 --> 00:19:17.760 AUDREY SCHULMAN: Yeah HEET might, at some point 00:19:17.760 --> 00:19:20.160 have a through Sierra Club, Massachusetts 00:19:20.160 --> 00:19:24.362 have a handheld device with which you could check something 00:19:24.362 --> 00:19:26.486 like that combustible gas indicator for anybody who 00:19:26.486 --> 00:19:28.890 is on the ride yesterday. 00:19:28.890 --> 00:19:32.185 So you'd be able to check the gas in the soil 00:19:32.185 --> 00:19:37.020 to find out if a tree is being poisoned by gas-- et cetera. 00:19:37.020 --> 00:19:39.650 NATHAN PHILLIPS: And I can't forget-- someone, who was it, 00:19:39.650 --> 00:19:42.540 came up with the idea of a bike, a bike trailer. 00:19:42.540 --> 00:19:43.290 AUDIENCE: You did. 00:19:43.290 --> 00:19:44.835 That was your idea. 00:19:44.835 --> 00:19:45.710 NATHAN PHILLIPS: Huh? 00:19:45.710 --> 00:19:46.349 AUDIENCE: You were talking about it. 00:19:46.349 --> 00:19:46.820 That was your idea. 00:19:46.820 --> 00:19:47.080 NATHAN PHILLIPS: Oh. 00:19:47.080 --> 00:19:47.579 Well-- 00:19:47.579 --> 00:19:53.300 [LAUGHTER] So that would be amazing. 00:19:53.300 --> 00:19:55.640 And there's a reason for it. 00:19:55.640 --> 00:19:58.730 Because, as you mentioned, you know these mains, 00:19:58.730 --> 00:20:01.740 they can run, more times than not, 00:20:01.740 --> 00:20:03.830 they run kind of down the middle of the street. 00:20:03.830 --> 00:20:05.360 But they can go on sidewalks. 00:20:05.360 --> 00:20:07.240 They can go on angles. 00:20:07.240 --> 00:20:08.890 The service lines leak. 00:20:08.890 --> 00:20:11.285 And so much of what we've done has not 00:20:11.285 --> 00:20:13.660 been looking at service lines, the perpendicular, smaller 00:20:13.660 --> 00:20:16.130 pipes that go into the houses. 00:20:16.130 --> 00:20:20.890 So with a bike or a cart, or an ability to get on sidewalks-- 00:20:20.890 --> 00:20:24.680 and to be able to move around in Boston or Cambridge, 00:20:24.680 --> 00:20:27.397 you know, if you ride a bike, that's the most efficient way 00:20:27.397 --> 00:20:27.980 to get around. 00:20:27.980 --> 00:20:30.450 I mean, if there's a gridlock, you're just going around. 00:20:30.450 --> 00:20:30.950 So-- 00:20:30.950 --> 00:20:32.180 AUDIENCE: Baby carriages. 00:20:32.180 --> 00:20:34.410 NATHAN PHILLIPS: Or baby carriages. 00:20:34.410 --> 00:20:39.430 And so Picarro does sell a smaller unit than that one, 00:20:39.430 --> 00:20:40.520 it's like a backpack unit. 00:20:40.520 --> 00:20:43.225 But it could go in a Burly trailer, 00:20:43.225 --> 00:20:46.670 or it could go on your back while you're riding a bike. 00:20:46.670 --> 00:20:47.694 So I would love that. 00:20:47.694 --> 00:20:49.360 It would be the first one in the nation, 00:20:49.360 --> 00:20:50.920 and I think it would be amazing. 00:20:50.920 --> 00:20:53.520 So if we can crowdsource that, generate some funds, 00:20:53.520 --> 00:20:54.515 that would be great. 00:20:54.515 --> 00:20:56.389 AUDIENCE: Well, couldn't the existing Picarro 00:20:56.389 --> 00:20:59.810 that you had in the van, can that be mounted, 00:20:59.810 --> 00:21:02.817 that and the battery or power, could that 00:21:02.817 --> 00:21:05.090 be mounted on our trailer behind a bike? 00:21:05.090 --> 00:21:06.520 NATHAN PHILLIPS: Yeah, it could. 00:21:06.520 --> 00:21:11.150 We could actually make a video with that, 00:21:11.150 --> 00:21:15.590 and that would be like, let's do it better-- 00:21:15.590 --> 00:21:19.000 because what you would use there is, like a garden cart, 00:21:19.000 --> 00:21:21.530 with those big balloon knobby tires 00:21:21.530 --> 00:21:26.244 to provide some shock absorption. 00:21:30.330 --> 00:21:31.830 AUDIENCE: Yeah, actually let me make 00:21:31.830 --> 00:21:35.180 a point of some order, which is now that we-- 00:21:35.180 --> 00:21:37.590 I think the formal portion of your presentation 00:21:37.590 --> 00:21:39.530 is done, right? 00:21:39.530 --> 00:21:40.530 AUDREY SCHULMAN: Right. 00:21:40.530 --> 00:21:42.030 AUDIENCE: So I think that we can now 00:21:42.030 --> 00:21:44.107 ask questions of all the speakers, not just-- 00:21:44.107 --> 00:21:45.940 NATHAN PHILLIPS: After giving Audrey a hand. 00:21:45.940 --> 00:21:50.820 [APPLAUSE] 00:21:50.820 --> 00:21:52.370 Can we have Susan's last question? 00:21:52.370 --> 00:21:55.785 AUDIENCE: I just was wondering because, on the field trip, 00:21:55.785 --> 00:21:58.510 I learned what the symbolism is by the gas company, 00:21:58.510 --> 00:22:01.000 and what kind of cast iron, it was written on the sidewalk 00:22:01.000 --> 00:22:01.500 here. 00:22:04.620 --> 00:22:11.550 If the company has the infrastructure in its archives, 00:22:11.550 --> 00:22:15.250 is there enough of a relationship 00:22:15.250 --> 00:22:19.130 between the age of the pipe and the material to know the leak, 00:22:19.130 --> 00:22:22.550 so you could make big assumptions about, OK, 00:22:22.550 --> 00:22:26.927 if you know that, then you don even have to do the monitoring. 00:22:26.927 --> 00:22:29.510 AUDREY SCHULMAN: The Department of Environmental Protection is 00:22:29.510 --> 00:22:32.140 making that exact point, in terms of basing all 00:22:32.140 --> 00:22:36.650 of the state-wide greenhouse gas methane emissions based 00:22:36.650 --> 00:22:39.850 on exactly that calibration-- miles of cast iron, 00:22:39.850 --> 00:22:44.710 miles of bare steel, et cetera, and making an assumption that-- 00:22:44.710 --> 00:22:49.270 they know the exact rate of emissions per mile of cast iron 00:22:49.270 --> 00:22:52.040 main, and that they don't even have 00:22:52.040 --> 00:22:56.500 to check, either top down, or bottom up, either. 00:22:56.500 --> 00:23:00.310 And I think that's-- 00:23:00.310 --> 00:23:05.350 you could make a guess at that, but you 00:23:05.350 --> 00:23:10.560 have to check to make sure it's right. 00:23:10.560 --> 00:23:12.810 NATHAN PHILLIPS: Yeah, they call the emissions factors 00:23:12.810 --> 00:23:14.350 and activity factors. 00:23:14.350 --> 00:23:17.350 And multiply A by B and get a leak rate. 00:23:17.350 --> 00:23:20.670 And these, I call them fudge factors, they basically say, 00:23:20.670 --> 00:23:23.860 cast iron has this many leaks per linear mile. 00:23:23.860 --> 00:23:25.456 That's your emissions factor. 00:23:25.456 --> 00:23:26.830 Well, how many miles do you have? 00:23:26.830 --> 00:23:29.551 That's your activity factor, multiply a by d, 00:23:29.551 --> 00:23:30.550 there is your leak rate. 00:23:30.550 --> 00:23:34.330 But those are based on very old-- 00:23:34.330 --> 00:23:36.835 not just old data, but very sparse data. 00:23:36.835 --> 00:23:39.960 AUDIENCE: But can you calibrate that with you leak data? 00:23:39.960 --> 00:23:41.710 NATHAN PHILLIPS: Yeah, that's we're doing. 00:23:44.191 --> 00:23:45.940 AUDREY SCHULMAN: I don't think it has much 00:23:45.940 --> 00:23:48.360 to do with each other. 00:23:48.360 --> 00:23:50.870 The Department of Environmental Protection emissions factors 00:23:50.870 --> 00:23:54.340 make it look like-- the problem is solved! 00:23:54.340 --> 00:23:56.320 And I don't think that that's true. 00:23:56.320 --> 00:23:59.410 AUDIENCE: There are [INAUDIBLE] emissions factors, right? 00:23:59.410 --> 00:24:03.790 So they are from the industry, and they're way outdated. 00:24:03.790 --> 00:24:06.619 Like, this is true, they're outdated for refineries, 00:24:06.619 --> 00:24:08.910 so when they go out and do modern testing on refineries 00:24:08.910 --> 00:24:11.022 they see the tanks leak at much higher rates 00:24:11.022 --> 00:24:12.730 than their emissions factors account for. 00:24:12.730 --> 00:24:15.340 NATHAN PHILLIPS: So there's a really interesting point 00:24:15.340 --> 00:24:17.750 the Commonwealth of Massachusetts 00:24:17.750 --> 00:24:21.142 apparently has done an enormous job at cleaning up our methane 00:24:21.142 --> 00:24:23.400 leak problem because, what they did was, 00:24:23.400 --> 00:24:29.470 the DEP utilized an early set of emissions factors natural gas 00:24:29.470 --> 00:24:33.940 leakage from the mid 90s, and then one that 00:24:33.940 --> 00:24:38.590 was much lower, from 2015 publication, 00:24:38.590 --> 00:24:42.930 and they linearly interpolated an emissions factor, so that-- 00:24:42.930 --> 00:24:46.437 they hardwired in a reduction because two studies 00:24:46.437 --> 00:24:48.020 showed two different emissions factors 00:24:48.020 --> 00:24:49.730 for the same kind of pipe. 00:24:49.730 --> 00:24:52.360 So result you get, it appears to make it look like we've 00:24:52.360 --> 00:24:55.464 done really, really well. 00:24:55.464 --> 00:24:57.630 AUDREY SCHULMAN: Kind of like, everything is solved. 00:24:57.630 --> 00:25:00.170 And part of the way they did they was, they got rid 00:25:00.170 --> 00:25:06.734 of superemitters, or one of the studies discarded any outliers. 00:25:06.734 --> 00:25:08.400 NATHAN PHILLIPS: Right, so the emissions 00:25:08.400 --> 00:25:14.280 factors are based on leaks are distributed like this. 00:25:14.280 --> 00:25:19.050 But what we know is that leaks are distributed like that. 00:25:19.050 --> 00:25:21.390 They're long tail with a few-- 00:25:21.390 --> 00:25:23.540 AUDIENCE: I mean, I would say that the normal 00:25:23.540 --> 00:25:30.099 versus long tail is an error across so many problems 00:25:30.099 --> 00:25:31.206 and industries. 00:25:31.206 --> 00:25:33.167 NATHAN PHILLIPS: Yes. 00:25:33.167 --> 00:25:35.500 AUDREY SCHULMAN: And we can all take a look at this data 00:25:35.500 --> 00:25:36.666 and make a guess as to where 00:25:36.666 --> 00:25:38.940 the long tail problem is. 00:25:38.940 --> 00:25:40.504 It's fairly apparent. 00:25:40.504 --> 00:25:43.345 AUDIENCE: So it's 50% from 7%? 00:25:43.345 --> 00:25:44.720 NATHAN PHILLIPS: That's what we-- 00:25:44.720 --> 00:25:46.840 Margaret Hendrick did a study-- 00:25:46.840 --> 00:25:51.360 that we did together-- that 7 of 100 leaks 00:25:51.360 --> 00:25:55.390 accounted for 50% of the gas loss. 00:25:55.390 --> 00:25:58.500 AUDIENCE: If you take this data as kind of the sample, 00:25:58.500 --> 00:26:01.560 and multiply by the number of rows and pipelines, 00:26:01.560 --> 00:26:04.445 and you try to match it with entire methane 00:26:04.445 --> 00:26:08.150 inventory of the US, just to see if the numbers are 00:26:08.150 --> 00:26:09.400 the same orders of magnitude-- 00:26:09.400 --> 00:26:10.650 NATHAN PHILLIPS: Yeah, we did. 00:26:10.650 --> 00:26:14.660 Not with the entire US, but we did it with Massachusetts 00:26:14.660 --> 00:26:17.300 AUDIENCE: [INAUDIBLE] 00:26:17.300 --> 00:26:21.000 NATHAN PHILLIPS: Yeah, so we found 00:26:21.000 --> 00:26:24.750 that, if we took the chamber measurements of leaks, 00:26:24.750 --> 00:26:27.120 100 leaks, and we just kind of multiplied that out 00:26:27.120 --> 00:26:32.060 by the frequency of leaks that we got previously-- 00:26:32.060 --> 00:26:37.540 that amount is consistent with other estimates, 00:26:37.540 --> 00:26:43.080 and are about one third of the total methane 00:26:43.080 --> 00:26:47.840 emissions estimated for the Commonwealth of Massachusetts. 00:26:47.840 --> 00:26:50.240 One third. 00:26:50.240 --> 00:26:55.950 This collaboration, we have to me, and with Mothers Out Front 00:26:55.950 --> 00:27:01.170 as a kind of hybrid advocacy science 00:27:01.170 --> 00:27:04.710 nonprofit kind of coalition, I've 00:27:04.710 --> 00:27:07.470 never been involved in anything like that, 00:27:07.470 --> 00:27:10.670 and it's just been the most fulfilling kind of partnership 00:27:10.670 --> 00:27:12.560 for research science and policy. 00:27:12.560 --> 00:27:14.110 AUDREY SCHULMAN: Yeah.