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Aconsulting <br /> ,,.• engineering firm <br /> have taken months and emn- + handles day-to-day <br /> pletely disrupted the tourist <br /> operation of the <br /> vacuum system and <br /> traffic that is vital to the local fi A;. treatment facility. <br /> economy.With the smaller- ram <br /> diameter vacuum lines that <br /> do not require a constant <br /> downward slope,trenches <br /> can be much narrower and <br /> shallower,usually 1.2 to 1.8 in <br /> (4 to 6(t)in depth,so instal- s. <br /> lation time is greatly reduced, ,, <br /> and far less heavy equipment <br /> is required. , <br /> Vacuum sewer technol- p""„a., `r-- A'" i ,:ik` <br /> ogy relies on differential air <br /> pressure to move wastewa- <br /> ter through sewer system - it <br /> mains.The process begins <br /> when wastewater flows from --- �- <br /> each house by gravity to a ich is vacuum structure,commonnlyc hQ es cd a an <br /> ve be co <br /> nnected <br /> wh ted The twa wastewater,where it moves then sotrapidly throped to the ugh he line that <br /> located nearby.Typically, <br /> to a single valve pit Each valve pit is equipped with a buildups of grease or sludge are rare.. <br /> vacuum interface valve that activates when wastewater in The Provincetown vacuum system includes a total of <br /> the lower sump reaches a predetermined level,typically 8.8 for(5.5 in!)of PVC pipe,ranging from too to 250 min <br /> ---"" -38 L(10 gal).When the valve activates,wastewater enters- -(4 in.to 10 in.)in diameter.There are approximately 250 <br /> = ' tfie-collector-line,followed by a volume of air.A central valve pits in system.The vacuum station;which is <br /> attractive building in the downtown area, <br /> -station maintains vacuum pressure within the sewer located in an <br /> main collection lines.The wastewater forms a slug that is has a 22.7-m'(6000-gal)tank and two wastewater pumps, <br /> driven by the air through the sewer mains to the central as well as four 18.6-kW(25-hp)vacuum pumps.There <br /> - has not been a single complaint about the station since it <br /> opened in 2003. <br /> Day-to-day operation of the vacuum system and treat- <br /> ment facility is handled by a consulting engineering firm. <br /> .Valve Initial operator training was provided by the vacuum <br /> Pit Package system manufacturer. <br /> Checkerboard District <br /> ;;. One of the unique aspects of this project is the"check- <br /> . erboard"sewer district,in which residents can opt in. <br /> Before installation began,a letter was circulated to prop- <br /> y <br /> erty owners explaining that a new sewer system was about <br /> ., •�� - to be installed.Because many residents were in compli- <br /> ance with Title 5,they were not required to connect to the <br /> _ new,system.Participation was voluntary. <br /> Approximately 340 property owners responded that <br /> 7r , y- they wanted to be connected to the new system.However, <br /> by the time construction was finished,more than500 cus- <br /> tomers were on-line.It seems that everyone now wants <br /> to be connected,which is a tribute to a system with near <br /> • >'1 �� flawless performance during the past 3 years. <br /> .}, The treatment plant currently has a capacity of 1890 <br /> m'jd(500,000 gaud)but easily can be expanded to treat <br /> 1 2840 ma{d(750,000 galJd).Like all aspects of the new sewer <br /> system,expandability was built into the plan. <br /> MAY 2007 40 <br /> ©20fo water Environment&'I'erhnologp All rights reserved <br /> t <br /> i <br />