AWWA WQTC64059

Poseidon Resources Corporation has proposed an ocean desalination plant in Carlsbad,California that would produce up to 50 million gallons per day of potable drinking water fortransmission to the City of Carlsbad water supply system. This seawater desalination processwould produce treated water that varies in quality from the City of Carlsbad's typical imported,treated surface water supply in several respects. The water quality of the reverse osmosis (RO)permeate would generally contain lower total dissolved solids, calcium concentrations,alkalinity, and disinfection byproduct formation potential, as well as higher concentrations ofbromide, sodium, and chloride ions than the imported water supply.The purpose of the corrosion pilot study was to compare corrosion indicators for conditioneddesalinated seawater with those of the imported water from the Metropolitan Water District ofSouthern California (MWD). Two primary scenarios were evaluated over a six-month period foreach water source, includingcontact with typical household plumbing materials (copper pipe and brass water servicemeters) using a diurnal flow regime representative of household consumption, andcontact with typical distribution main materials (cement mortar-lined pipe and gatevalves) at a representative, constant flow rate.Three different configurations of pipe systems were constructed to compare the corrosivity ofRO permeate and the imported MWD water supply on a variety of distribution system andresidential plumbing materials:flow-through systems consisting of new copper pipe and system-harvested residentialbrass water service meters (brass meters);recirculation systems of new cement mortar-lined steel pipe; and,recirculation systems containing harvested, cast iron distribution system gate valves.Each of the three test system configurations was replicated in four independent pipe testing loopsor lengths. Two of the four loops or lengths in each set received conditioned RO permeate andthe other two received MWD water. MWD water was acquired from a connection to a potablewater line at the site. Due to the inherent imprecision of corrosion processes and corrosion pilottesting, the pilot facility included a duplicate of each pipe loop or test system for each waterquality. The paper provides a schematic of the pipe test system layout. Includes 8 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

16

File Size:

1 file , 550 KB