Related Links: Pipeline Opponents Say Project Is No Longer Economically Justifiable PSB halts Vermont Gas pipeline project along VELCO route Vermont Gas's contentious natural-gas pipeline extension to connect service areas in Chittenden and Franklin counties is temporarily on hold. The Vermont Public Service Board (PSB) on July 25 ordered the utility to halt construction until it filed a soil management plan.Opponents allege construction in VELCO's transmission-line corridor could possibly release hazardous chemicals present in the soil. Pentachlorophenol (PCP), a wood preservative used to treat utility poles, has been detected near the pipeline route in a Monkton resident's well, according to
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.