APPLICATION SYSTEMS ENGINEERING
|New USEPA Rules|
|Houston, Tx. Case Study|
Public Water Treatment methods vary, depending on characteristics of the raw source water used. Ground water may require little or no treatment to meet Federal & Local regulations. Surface waters (rivers, lakes, reservoirs) require added treatment because they are exposed to the environment, eg. rain runoff through fertilized fields. Surface water contamination influences ground water.
Coagulation/Flocculation of the raw water particulates is used by adding Alum, Polymers & Salts to join smaller particles together to create larger particles for their sedimentation & removal. Basic filtration to remove remaining particles, organics & micro-organics is often augmented by Ion Exchange & Activated Carbon Beds. Disinfection to kill microbes prior to distribution may be accomplished by chlorine, chlorine dioxide, chloramines or ozone.
Total Organic Carbon Analysis is the primary screening & monitoring method for water quality. Federal Regulations require monitoring for more than 83 contaminants, consisting primarily of volatile organic compounds (VOCs) synthetic organic compounds (SOCs) & inorganic compounds (IOCs), in addition to microbial/bacterial organisms.
Distribution Systems consist of piping & pumping networks to deliver drinking water to homes, businesses & industrial users. Contamination caused by such occurrences of pressure failures causing leakage, piping breaks, seal failures & micro-organism growth continue as normal events, however, National Security interests have heightened concerns for the safety of public drinking water.
WHAT NEEDS TO BE MONITORED TO MAINTAIN DRINKING WATER SAFETY? Various studies by Homeland Security & Others have tried to define a strategy of a network of water analyzers & develop algorithms which could trigger an alert that the drinking water system was under attack. While these studies & analyses have been on-going, initial consensus appears to be narrowing to the following sensors/analyzers:
Total Organic Carbon (TOC) pH Turbidity
Electrolytic Conductivity Chlorine