Determination of vertical and horizontal pathways of injected fresh wastewater into a deep saline aquifer (Florida, USA) using natural chemical tracers [Détermination de cheminements verticaux et horizontaux deau usée traitée injectée dans un aquifère salé profond (Floride, USA) en utilisant des traceurs chimiques naturels]
Walsh V.,071 SW 38th Ave |
Walsh V.,Florida International University |
Price R.M.,Florida International University
Hydrogeology Journal | Year: 2010
Two deep-well injection sites in south Florida, USA, inject an average of 430 million liters per day (MLD) of treated domestic fresh wastewater into a deep saline aquifer 900m below land surface. Elevated levels of NH 3 (highest concentration 939 μmol) in the overlying aquifer above ambient concentrations (concentration less than 30 μmol) were evidence of the upward migration of injected fluids. Three pathways were distinguished based on ammonium, chloride and bromide ratios, and temperature. At the South District Wastewater Treatment Plant, the tracer ratios showed that the injectate remained chemically distinct as it migrated upwards through rapid vertical pathways via density-driven buoyancy. The warmer injectate (mean 28°C) retained the temperature signal as it vertically migrated upwards; however, the temperature signal did not persist as the injectate moved horizontally into the overlying aquifers. Once introduced, the injectate moved slowly horizontally through the aquifer and mixed with ambient water. At the North District Wastewater Treatment Plant, data provide strong evidence of a one-time pulse of injectate into the overlying aquifers due to improper well construction. No evidence of rapid vertical pathways was observed at the North District Wastewater Treatment Plant. © Springer-Verlag 2010.
Terrero R.,071 SW 38th Ave. |
Arrebola V.E.,071 SW 38th Ave. |
Aguiar L.,071 SW 38th Ave. |
Lovett R.J.,071 SW 38th Ave. |
Coates R.A.,071 SW 38th Ave.
Journal - American Water Works Association | Year: 2013
The Miami-Dade Water and Sewer Department (WASD) adopted a proactive infrastructure renewal program to address its aging water and sewer infrastructure. The predominance of prestressed concrete cylinder pipe (PCCP) was the major reason of aging infrastructure. WASD implemented Florida's Infrastructure Assessment and Replacement Program (IAARP) which strives to find and implement the best available inspection and rehabilitation technologies to address damaging deficiencies in the large diameter buried pipe of its pipeline network. WASD performs four main functions, such as regular leak detection on large diameter transmission mains, electromagnetic condition assessment, structural risk analysis and ongoing monitoring of PCCP pipelines through acoustic fiber-optic monitoring technology. By beginning a complete renewal program, WASD aims to prevent major system failures, increase service reliability, and extend the useful life of its assets.