captioning sponsored by wnet >> sreenivasan: on this edition foturday, february 23: clashes at the venezuelan border id trucks try to enter. the catholic church sexual abuse summit continues at the vatican. and in our signature seg tnt: new yorkkles contaminants found in drinking water. next on "pbs newshour weekend." >> pbs newshour weekend is made possible by: bernard anirene schwartz. sue and edgar wachenheim iii. seton melvin. the cheryl and philip milstein family. dr. p. roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provided

by mutual of america-- designing customized individual ctand group retirement pro that's why we're your retirement company. ditional support has bee provided by: and by the corporation for public broadcasting, and by nt butions to your pbs station from viewers like you. thank you. isfrom the wnet studios at lincoln center in new york, hari sreenivasan. >>ni sreenivasan: good e and thank you for joining us. tension continues to rise in ve wnezuela today overther humanitarian aid will be allowed into the country. the national guard tear-gassed ters from both venezuela and colombia who tried to reach bridges between the countries. the clashes happened in the bordering cities of urena incu venezuela and ta in colombia. on the colombian side of the tebridges, opposition prot tried to escort trucks with emergency food and medic aid into venezuela using what leaders call a "humanitarian avalanche."

on the venezuelan side of the harder the venezuela national guard injured moretwo dozen people as protestors set fire to buse pbs newshour special correspondent nadja drost is in urena, venezuela. >> i saw one bus being burned and crash into a house, and then the house was set on fire. so i think that for protesters who nted this to be a peaceful event, that thatnc c was lost when some of the actions of the protesters turned violent. however, we did see an attempt at a negotiation. i was with a group ofwo congressmen ann from the national assembly, which is currently held in contempt by the maduro government, and they were trying to walk veryalmly towards the national guard, and the national guard responded by tossing tear gas, and everybody rtarted runni back and has

become dissed once again. so it's unclear as to whether those members of the nional assembly are going to make another attempt to try to reach the national guard and have some kind of dialogue with them. >> sreenivasan: venezuela's presiden the ais maduro says >> sreenivasan: venezuela's president nicolas maduro says thaid is a precursor to an american invasion and continues to pledge to keep the assistance out. earlier, opposition leader juan guaido appeared in cucuta with the presidents of columbia and paraguay and called on tops and supporters of maduro to allow the aid into venezuela. the "new york times'" ande bureau chief nicholas casey joins us now from cucuta, colombia. from cucuta, colombia, via skype. >> basically, the opposition has coen trying to get food past s maduro's blockades at the borders and they haven't been able to. they've amassed hunof people on some of the bridges. re have beenke the thousands, but maduro has been pretty strict about not letting the full number of aid shipments get in. on one border, there was some

aid that got in, but it got burned by the soldiers on the other side. and here, this bridge i'm on, they've been trying to make the aid get through, but it hasn't been able to get past basiyca k huge wave of tear gas. there has been r throwing. the food behind me doesn't look like it is getting anywhere today. >> sreenivasan: people on the colombia side of the bridge are throwing rocks, a the venezuelan military is throwing tear bass back at them. >> exactly. it started with the venezuelan tear gas, and it got to the point where you had hundreds of peoples toking rocks to people on the bridge andin thrback to the venezuelan military. it's gotten to be pretty messy. the idea behind this was that it was going to be a peaceful march,nd people were going to come to the bridge and try to coilince theitaryings who also suffers from shortages of food and medicine, to join them, but it doesn't look like it's going to get resolved. >> sreenivasan: nicolas maduro this afternoon severed basicly

all diplomatic and political ties with colombia. he's saying, look, this is a staging ground for violence against venezuelans. >> and this is huge because colombia and venezuela have been at loggerheads many times before. they've even had troops on their borders during hugo chavez's time. severing ties with the country right next to you is a big deal. >> sreenivasan: does juan guaido he a plan "b"? i mean, this ended up becoming a bit of an apex-- this day we are trying to get this humanitarian aid thto country, and this was the day where maduro was going to try to amass his forc s to t stop it. >> if he's got a plan "b," heo hasn't told ane hardly what it is at this point. there was only a plan "a,s " whh get this border open and to get the aid on to the other side of the border. bew what we're look at might something much longer, standoff here, the trucks just sort of

cttting there, sort of a trench-style confhere both sides dig into these border bridges and nothing passes through them >> sreenivasan: earlier this week, you cataloged the migration or the exodus out of venezuela. at this point, they are not able to get out of any of these land routes. >> well, no, not cucuta. that route that i was on with the migrants starts here, and then goes up to a 12,000-foot pa in thendes. people used to be able to walk through this, you know, whenever they wanted to and start their journey, no matter how tough it was. if they wanted to start that today, they wouldn't be able to do that. >> sreenivasan: the sentiment there, the people were optimistic i assume this morning, when they wanted to see ipments go through, as the day has pro'sgressed, what what are people thinking andth feeling re? >> well, i think people are trying to watch and see what's going to happen next, whether this food will somehow start to make it through, will more people start to defect from the national guard? ectionsave been some def here.

it's a big crowd that's sort of amassing here again. it's-- situations are changing by the minute. but, yeah, we'll have to see. >> sreenivasan: you can tell me a litele bit about th soldiers that were supposed to be on those bridgees from the venezuelan side who defected today? >> yes, i was actually here when some of this happened. suddenly, there were cheers and commotion,nd members of the national guard started to come over. thhee were eight of tm. they were brought over to an immigration building on the other side of the border. they essentially had defected to this side and they're going to colombia >> sreenivasan: because it's got to be hard for some of the soldiers who have families who e aren't gettiugh to eat, that this humanitarian aid would benefit. >> this is the opposition's argument, which is that the soldiers, which are throwing the tear gas, also are suffering agem same problems the aver venezuelans do, which they don't have food for their ownmi es. this has been the offer of juan guaido to offer people amnesty if they come over to this side. and, you know, i think you'll see probably more of these defections as astimes. >> sreenivasan: all right. y

"nk times'" nicholas casey joining us via skype from colombiaia tonight thanks very much. >> thank you. >> sreenivasan: the thd day of the vatican summit on sexual abuse brought strong condemnation of church leadersd arges of cover-ups. a german cardinal admitted church files about abusers were destroyed or never created. isd a prominent nigerian nun had tough crit >> yes, we proclaim the ten commandments and "parade ourselves" as being the custodians of moral standards and values and good behavior in hypocrt times? esciety. yes. but why did we keep silent for so long? pi sreenivasan: for more on venezuela's develo political crisis, visit pbs.org/ur. >>reenivasan: the summit o sexual abuse in the catholic church produced startldag testimony

tomorrow-- the final day of the four-day conference-- the pope is scheduled to speak. joining us now from rome via skype is newshour special correspondent chris li sponsibility and on.oing on accountability and transparency. what caught your ear today? >> well, a couple of things.ne i mean, of the most alarming events was when german cardinal by the way of marx admitted to the fact that the catholic church has, in fact, destroyed evidence of seabuse in the past. this is probably no huge shock to the thousands of victims who have come forward in the united states let alone the world in the past decades. but for the church to admit participating in a cover-up is t'g. i mean, i thinks also a t popeent to the fact tha francis has said that the church has to make concrete action and 'fessing up to the fact that its rical are dirty in the cle sex abuse scandals is part of that process.

>> sreenivasan: there was also a nun that spoke today. what did she have to say? >> so a nun from nigeria addressed the conference, which in and of itself is prettnt monu. she made a point of saying usually these are men speaking dbefore you. he went on to tell everybody there-- we'e talking about roughly 200 church leaders from around the world-- that this is an incredible problem, and that that needs to come to anvand. >> sreen: so pope francis is sitting there listening to all this. he's expected to speak tomorrow. are there any expectations of what he could say or what kind of actions the church could take? >> tre are incredibly high expectations for this summit. however, the pope and every o lead this event have gone out of their way to basically tamp down those expectations as well. i mean, this is the catholicen church at th of the day. it's been around for 2,000 years.

you cannot turn a battle ship on a dime. this conference is not going to change things ovehaight. that'sthey've been saying over and over and over again. one ofhe things that raised expectations coming into this tonference was the fact tha pope francis defrocked afo cardinal, thmer archbishop of washiton, d.c., for his past sexual misconduct. that sent huge shock wavethroughout the cac chump, and also throughout the community of survivors and victims. but the tbig question onir mind has been, "well, is this just a bone that the pope is throwing us to kind of, you know, keep us at bay for some time? or is this the beginning of something new?" and if he was trying to kind of silence the masses of survivors, that definitely hasn't worked in the short term. rome has been awash with

hundreds of survivors from around the world w have been protesting outside st. peter's square, demanding zero tolerance, demanding immediate prtion-- not just defrocking of sts and other prellates. i mean, the pope has admitted the bishops have been predats. i mean, look at the archbishop of-- the former archbishop of washington d.c. so thee-- these are crimes that go all the way to the top. llvictims are not ing to just, you know, see them kicke upstairs, which has been theas habit of the-- in other dords, just passing priests an other prelates to other parishes, and sometimes even promoting them. ed, they want to see concrete action, people hanver to authorities, civil authorities who can prosecute, rather than the church doing its old, you know, traditional way of handling things, which is internally, and then victims very rarely seeingind of punishment or serious

consequences come out of that. >> sreenivasan: all right chris livesay joining us via skype from rome tonight. thank you so much. >> thank you, hari. >>reenivasan: the environmental protection agency recently announced iwould start the process of setting drinking water standards for two widely found chemicals by the end of this year. p.f.o.a and p.f.o.s were used to make things like non-stick cookware and water repellent materials. they have since been linked with cancer, kidney disease, and weakened childhood immunity. but the federal gove regulating new chemicals in drinking water is uncommon. it's a task often left- if it happens at all- to the states. in tonight's signature segment we are updating a report on drinking water safety and new york state's push to regulate a chemical found in drinking water around long island. it's a story about how one region is trying to clean up its water, and how costly it can be.

>> sreenivasan: so, this is one of the more contaminated well sites? >> yeah. >> sreenivasan: engineer rich humann is showing me a water ur fridge.the water filter in tstalled in 1990, they use carbclean water polluted by decades-old industrial t tivity. ngt they aeffective at removi new contaminant that has been detected in long island's water. so what are these going to do? >> so, this is the ad oxidation system that the bethpage water dsttrict had inled primarily to deal with 1,4-dioxane. >> sreenivasan: 1,4-dioxane is a chemical found in degreasers, paint-strippers, solvents, and e consumer products like detergents and soaps. it's classified as a "likely human carcinog" by the environmental protection agency, associated with navity, liver and gall bladder tumors in animal studies. is there a gap between what's tested and what's in the water? >> the answer is yes. we have more emerging chemicals.

we have to mandate that those chemicals are tested for. >> sreenivasan: adrienne esposito rune citizens campaign for the environment, which is based on long island. it has been raising alarms about the lack of regulation around 1,4-dioxane and other d unregulantaminants in drinking water. >> each year we know a little libit more, we test le bit more, and we find a little bit more and that's a little bit scary. >> sreenivasan: between 2013 and 2015, the e.p.a. requiredr very large waovider in the u.s. to test for 1,4-dioxane. that's the first step in whether or not a contaminant will be regulated under the safe drinking water act. esults showed that long island was a hot spot. mf ore than 70%ter authorities here had levels of an1,4-diabove .35 parts per billion. that's the level that the e.p.a. calculates poses a lifetime, one-in-a-million increased chance of developing cancer. at may not sound like th

high a risk level, but many sites here on long island had levels way above the ones associated with that long-term cancer risia in fact, off here in hicksville had to shut down this well in 2015 becau it was found to have levels of 1,4- dioxane that were the hiest in the country, amounts that were nearly 100 times higher than that one-in-a-million risk level. but 1,4-dioxane's presence in drinking water doesn't mean it'll necessarily be regulated at the federal level. the e.p.a. says it will not make any final determination until at least 2021. >> the federal government didn't take a lead role in wanting to regulate it. so the state decided that due to the high occurrence on long island that we were going to take a closer look. sreenivasan: stan carey is the superintendent of the massapequa water district on long island. in 2017, he was appointed by governor andrew cuomo to be on the new york state driing water quality council. the council was charged with coming up with a lev under which 1,4-dioxane and two other unregulated chemicals should remain. >> do you have any numbers if

that standard was set lower? >> sreenivasan: in december 2018, the council recommended that the maximum allowable level of 1,4-dioxane in drinking water bshouone part per billion. in other words, about three sotimes the level ated with that one-in-a-million cancer risk. carey says he supports the recommendation of the council, but he actually would have allowed for me 1,4 dioxane to e in the water. he says other chemicals aren't regated so stringently. >> i don't want to, you know, jeopardize public health. i wasn't trying to do that. but other contaminants at are regulated, they are not legulated at the one-in-a- million cancer risl. vinyl chloride, t.c.e., trichloroethylene, they're regulated in the range closer to one-in-ten-thousand. so putting it in perspective, that's what i was using as a comparison. >> sreenivasan: carey also says thathtven though the limit mig be one part per billio

state ordinarily makes water suppliers take action before a chemical reaches the maximum level. meaning in practice, water utilities will be forced to meet d then there's the potential cost for water providers and ratepayers. >> you have to take in the cost of the treatment and there has to be a balance of actually esat's feasible to implement. >> sreenivasansito says the proposed new limit, which would be the first firm regulation on 1,4-dioxane in the country, will protect new yorkers. >> right now there ino standard. so for the public to gain that icvel of protection, that's a signift advancement of public health protection s >>enivasan: esposito acknowledges the challenge is how water providers will pay to meet this new state standard. >> many of the water supplies do do due diligence. i think they actually want to know what's in the drinking water. the oblem is when they find out something's there, the cost of the treatment. >> sreenivan: new york state allocated $2.5 billion towards water infrastructure in 2017. and last october, nce state anno $200 million of that money would fund treatment for

emerging contaminants, including 1,4-dioxane. at bethpage's plant six, the level of 1,4-dioxane tested eight times higher than new york's proposed threshold. >> so two million gallons a day twater can ated through this set of reactors. >> sreenivasan: the water dtrisict is piloting this advanced oxidation process, or a.o.p., and splitting the nearly $3 million cost with the state. t ihe system, whistill being tested, is one of the only known ways to remove 1,4-dioxane from water >> one of the more significant challenges in dealing with 1,4- dioxane is it's highly soluble, which makes it difficult to come out of water through some traditional treatment techniques. >> sreenivasan: humann showed us how it works. hydrogen perox added to the untreated water. the water is then run past u.v. lamps. the process breaks down and removes the 1,4-dioxane from the water. >> you can do everything from a technical perspective and you can understand the theory andea how the ent supposed to work. but you know there's always the

practicality of the actual operation of the system. t >> sreenivasan: in fere are unknowns about how this technology even works. he center for clean wate technology at stony brook university, researchers are studying e system using a miniature version, and setting up a.o.p. pilot projects atitour water uts on long island. arjun venkatesan is the associate director r drinking water initiatives at the center. >> this is a simulated groundwater. we add known amounts of contaminants, in this case it's 1,4-dioxane, and the water is pumped through the reactor. this is set up in such a way that we can understand how quickly the dioxane degrades over tim >> sreenivasan: the center's researchers are also looking at chemical byproducts created when . light reacts with the contaminated water. >> we want to make sure the ad nced oxidation process system does not generate some toxic chemicals that we don't derstand yet >> sreenivasan: long island's industrial past plays a big role in its drinking water issues.

bethpage was home to a 600 acre complex where the us navy and defense contractor grumman, now northrop grumman, developed and built aerospace equipment from the mid-1930s to the 1990s. indiauswaste from the site has sunk down to the aquifer, which is the sole source of drinking water for nearly three million peoplong island. engineer rich humann says the y derground plume, as it's known, is a realat water providers like bethpage have to deal with. >> we're never going to get away, at least i'm going to say in myifetime from the fact that we've got the old navy/grumman property. nivasan: right. >> we've got one of the most significant groundwater contaminationlumes in the entire country that this water district has been impacted like no othe and dealing with the burden that frankly no water supplier should have to deal wit but they have no choice. >> sreenivasan: elsewhere on ong island, some water providers are suing the makers of 1,4-dioxane. since 2017, at least ten of em have filed lawsuits against dow

alemical, and two other chemic manufacturers. in a statement to nehour weekend, dow said, in part, that, "these lawsuits are without merit." the chemical industry more broadly downplays e risks from 1,4-dioxane. in a statement, the american chemistry council, an industry group, said, in part, it's" ...troubled by new york's... recommendation for 1,4 dioxane..." claiming that it's" ...neither scientifically jusfied nor economically feasible." and points out that in canada, the limit is 50 parts per billion, 50 times new york's proposed standard. meanwhile, in bethpage, officials tell us it's not just the contaminants they know t, like 1,4-dioxane, tha worry them. considering all of the other chemicals out there that have happened in the last 30 or 40 years. when scitarts to figure out how to detect those in the water. does that an we're going to have to build new tools like this just to be able to get that out ofur drinking water? >> that's if 1,4-dioxane as an indicator, then that's likely.

>> this is "pbs newshour weekend," saturday. >> sreenivasan: acting defense secretary patrick shanahan, joint chiefs' chairman, general joseph dunford, and other pentagon officials toured site on the border with mexico near el paso, texas, today. the department of homeland security requested defens department funding for construction of roads, replacement of vehicle barriers and pedestrian fencing, and installation of lighting. the pentagon has not yet decided whether to divert as much as $3.6 billion from military construction projects for border security. the russian news agency tass reported that north korean leader kim jong un left pyongyang by train today-- heading to vietnam ahead of his summit with president donald trump in hanoi this coming wednesday. preparations for the second summit between the two leaders cluded the official opening of an international media center in hanoi today. president trump is scheduled to leave for the summit on monday. the vote count is underway in nigeria after today's postponed-

presidential election began with problems. voters faced hours-long delays at polling stations across the country and there were reports of gunshots and explosions in some locations. the presidential election was deiginally planned for last saturday, buyed due to logistical difficulties. sihammadu buhari is seeking his second term as pnt of nigeria, africa's most populous cotry and largest economy. election observers say that preliminy results will be released next week. the united methodist church is beginning a meeting in st. louis today on w sex weddings and the ordination of l.g.b.t.q. clergy. nearly 900 delegates from around the world will vote on whether to lift church bans around l.g.b.t.q. ilusion for congregations in the u.s. votes that might lead to the church being split into three denominations. the united methodist church is one of the largest protestant denominations in the united states. in recent years membership in the u.s. has declined, but

globally, particarly in parts of africa, the church is growing. >> sreenivasan: join us tomorrow for an inside look and listen fuirom armstrong's archives- - now digitized and ready for new generations of micians. that's all for this edition of "pbs newshour weekend." i'm hair sreenivasan. thanks for watching. have a good night. captioning sponsored by wnet captioned media access group at wgbh access.wgbh.org >> pbs newshour weekend is made

poible by: bernard and irene schwartz. sue and edgar wachenheim iii. seton melvin. the cheryl and philip milstein family. dr. p. roy vagelos and diana t. vagelos. the j.p.b. foundation. rosalind p. walter. barbara hope zuckerberg. corporate funding is provide by mutual of america-- designing customized individual and group retirement products. tha's why we're your retirement company. additional support h been provided by: and by the corporation for public broadcasting, and by contributions to your pbs station from viewers like you. thank you. be more. pbs.

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♪ i let you do these things to