Hopefully none of the 90+ contaminants that the Environmental Protection Agency regulates in drinking water.
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16 NU Science
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7KLQNLQJ DERXW VZLWFKLQJ WR ERWWOHG ZDWHU" <RX PD\ ZDQW WR UHFRQVLGHU 6WXGLHV DUH VKRZLQJ WKDW ERWWOHG ZDWHU LV QRW VLJQL¿FDQWO\ FOHDQHU WKDQ WDS ZDWHU DQG PD\ FRQWDLQ KLJK OHYHOV RI GLVLQIHFWDQW E\SURGXFWV 8QOLNH WDS ZDWHU ZKHUH FRQVXPHUV are  provided  with  test  results  every  year,  the  bot- tled  water  industry  is  not  required  to  disclose  the  UHVXOWV RI DQ\ FRQWDPLQDQW WHVWLQJ WKDW LW FRQGXFWV Not  to  mention  that  bottled  water  costs  an  aver- DJH RI WLPHV PRUH WKDQ WDS ZDWHU SHU JDOORQ %HFDXVH VRPH FRQWDPLQDQWV DUH GDQJHURXV LQ VPDOOHU concentrations  than  others,  the  EPA  sets  an  amount  for  each  con- WDPLQDQW FDOOHG D 0D[LPXP &RQWDPLQDQW /HYHO 0&/ ZKLFK LV WKH KLJKHVW OHYHO RI D FRQWDPLQDQW WKDW LV DOORZHG WR EH SUHVHQW LQ GULQNLQJ ZDWHU 7KHVH DUH W\SLFDOO\ PHDVXUHG LQ PLOOLJUDPV SHU liters,  which  is  equivalent  to  parts  per  million  (ppm),  or,  for  very  potent  compounds,  in  parts  per  billion  (ppb).  MCLs  are  enforced  (3$ VWDQGDUGV 1DWLRQDO 3ULPDU\ 'ULQNLQJ :DWHU 5HJXODWLRQV 2WKHU FRQWDPLQDQWV WKDW PD\ VLPSO\ FDXVH FRVPHWLF HIIHFWV VXFK DV VNLQ RU WRRWK GLVFRORUDWLRQ RU DHVWKHWLF HIIHFWV LQ ZDWHU VXFK
per  billion. 7KH (3$ VD\V WKH UHJXODWLRQ ZLOO WDNH WZR \HDUV WR HQDFW DQG QR VSHFL¿F 0&/ KDV EHHQ DQQRXQFHG DV RI \HW 7ZR VWDWHV FXUUHQWO\ KDYH SHUFKORUDWH UHJXODWLRQV 0DVVDFKXVHWWV DW SSE DQG &DOLIRUQLD SSE DOWKRXJK WKHUH LV D PRYHPHQW LQ &DOLIRUQLD to  reduce  the  limit  to  just  1  ppb,  which  is  the  equivalent  of  a  half  RI D WHDVSRRQ LQ DQ 2O\PSLF VL]HG SRRO 7KH (3$ DOVR DQQRXQFHG WKDW WKH\ ZLOO EH UHJXODWLQJ DV D JURXS FDQFHU FDXVLQJ FKHPL- FDOV NQRZQ DV YRODWLOH RUJDQLF FRPSRXQGV ZKLFK DUH FKHPLFDOV that  include  trichloroethylene  (TCE)  and  tetrachloroethylene  (PCE)  as  well  as  other  industrial  contaminants  and  solvents.  In  WKH SDVW FKHPLFDOV KDYH EHHQ UHJXODWHG RQ DQ LQGLYLGXDO EDVLV EXW UHVHDUFK LV VKRZLQJ WKDW PDQ\ FRQWDPLQDQWV FDXVH FXPXODWLYH GDPDJH WR WKH ERG\ DQG WKH QHZ DSSURDFK LV WR DGGUHVV WKHP DV JURXSV  If  youâ&#x20AC;&#x2122;re  curious  about  test  results  from  your  local  water  VXSSO\ \RX FDQ FKHFN LW RXW RQOLQH DW KWWS ZZZ HZJ RUJ WDS ZDWHU ZKDWV LQ \RXUZDWHU -ÂJohn  Jamieson,  Chemical  Engineering,  2015
Digging Out Taking a look back at the last winter that buried Boston
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Whats on Tap?
as  taste,  odor,  or  color)  are  addressed  by  the  EPAâ&#x20AC;&#x2122;s  National  Sec- RQGDU\ 'ULQNLQJ :DWHU 5HJXODWLRQV ZKLFK DUH QRQ HQIRUFHDEOH JXLGHOLQHV ([DPSOHV RI LWHPV RQ WKDW OLVW LQFOXGH ]LQF LURQ S+ DQG PDQJDQHVH 7HVWLQJ LV GRQH UHJXODUO\ RQ ZDWHU VXSSOLHV WR PDNH VXUH WKDW WKH\ DUH FRQVLVWHQWO\ PHHWLQJ VWDQGDUGV IRU DOO FRQWDPLQDQWV 5HFHQWO\ WKH (3$ DQQRXQFHG WKDW LW ZLOO EHJLQ WR UHJXODWH SHU- FKORUDWH LQ GULQNLQJ ZDWHU RQ D QDWLRQDO OHYHO 3HUFKORUDWH LV D FRPSRQHQW LQ URFNHW IXHO Ã&#x20AC;DUHV DQG ¿UHZRUNV ,Q PRVW FDVHV perchlorate  water  contamination  has  been  caused  by  improp- HU GLVSRVDO DW URFNHW WHVWLQJ VLWHV PLOLWDU\ EDVHV DQG FKHPLFDO plants.  The  EPA  says  the  chemical  can  disrupt  the  thyroidâ&#x20AC;&#x2122;s  abil- LW\ WR SURGXFH KRUPRQHV WKDW DUH YLWDO WR GHYHORSLQJ IHWXVHV DQG LQIDQWV DOWKRXJK VWXGLHV DUH VWLOO EHLQJ FRQGXFWHG WR GHWHUPLQH LI WKH FRQFHQWUDWLRQV IRXQG LQ GULQNLQJ ZDWHU DUH KLJK HQRXJK WR FDXVH WKDW NLQG RI GDPDJH 7KH (3$ EHOLHYHV WKDW EHWZHHQ DQG PLOOLRQ $PHULFDQV LQ VWDWHV FRXOG KDYH SHUFKORUDWH LQ WKHLU ZDWHU ZLWK SDUWLFXODUO\ KLJK UDWHV SUHVHQW LQ 7H[DV DQG &DOLIRUQLD 7KH (3$¶V PRYH UHYHUVHV D MXGJPHQW E\ WKH %XVK DG- PLQLVWUDWLRQ ZKLFK GHFLGHG QRW WR UHJXODWH WKH FKHPLFDO EXW LQ- VWHDG UHFRPPHQGHG WKDW FRQFHQWUDWLRQ OHYHOV QRW H[FHHG SDUWV
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WKHUH KDG EHHQ YHU\ IHZ ZDUP VSHOOV SDVW WKH ¿UVW EOL]]DUG LQ 'H- cember. :KDW UHVXOWV LV SORZV DQG ORFDOV PHUHO\ SLOLQJ VQRZ on  top  of  snow  from  storm  after  storm.  The  few  spans  of  warm  ZHDWKHU WKDW RFFXU PHUHO\ PHOW WKH WRS OD\HU ZKLFK WKHQ IUHH]HV RYHUQLJKW DQG VHUYHV WR IXUWKHU LQVXODWH WKH VQRZ XQGHUQHDWK $OO RI WKLV DPRXQWV WR D YROXPH QLJKWPDUH :H FDQ H[SHFW ODUJH SDUN- LQJ ORW VQRZ SLOHV VXFK DV WKH RQHV LQ WKH &ROXPEXV ORW WR ODVW until  April.  The  snow-Âfarms  in  which  Boston  dumps  the  massive  DPRXQWV RI VQRZ FOHDUHG IURP VWUHHWV DQG SXEOLF ZDONV ZRQ¶W H[- pect  a  full  melt  until  mid-Âsummer. With  the  statistics  below  (data  provided  by  the  National  Weather  Service),  it  is  clear  what  made  this  December  and  January  differ- ent  that  ones  in  the  past.  The  temperatures  are  on  par  with  histori- FDO DYHUDJHV RQO\ GLIIHULQJ E\ GHJUHHV RU VR ,W¶V RXU VQRZIDOO that  has  burned  the  2010-Â2011  winter  into  our  memories.  January  snowfall  (38.3  inches)  was  only  5  inches  short  of  the  record  set  in  LQFKHV DQG QHDUO\ WULSOHV WKH KLVWRULFDO DYHUDJH inches). $ KLVWRULFDO QRWH WKH ZRUVW ZLQWHU %RVWRQ H[SHULHQFHG LQ UHFHQW PHPRU\ DQG WKH EHQFKPDUN IRU VQRZIDOO $UPDJHG- don,  was  the  winter  of  1995-Â1996.   Leaders  in  the  Boston  Public  :RUNV VHFWRU KDG EHJXQ WR FRPSDUH WR WKDW DUFKHW\SL- FDO QLJKWPDUH E\ PLG -DQXDU\ %\ WKH HQG RI -DQXDU\ WKH µ µ season  had  produced  15  more  inches  of  snow  than  we  have  now,  ZLWK ORZHU WHPSHUDWXUHV PHDQLQJ HYHQ OHVV PHOW /HW¶V MXVW KRSH these  statistical  anomalies  continue  to  occur  only  every  decade  RU VR RU ZH PD\ EH ZLWQHVV WR \HW DQRWKHU VLJQ RI GUDVWLF FOLPDWH FKDQJH KHUH LQ 1HZ (QJODQG   -ÂJames  Peerless,  Chemical  Engineering,  2011 NU Science 17