Drinking Water Treatment Exam 1

3 types of constituents

Particulates, ionic/dissolved species, gases

4 major pathogens

E. coli, Adenovirus, Cryptosproridum, Giardia

Common inorganic chemical species

carbonate species, hard water ions (calcium, magnesium), and regulated contaminants (nitrate, cadmium, mercury, arsenic)

The most critical group of organic pollutants

Natural organic matter (NOM) (aesthetic concern)

Synthetic organic chemicals (SOCs)

anthropogenic organics (ex PFAS)

Two types of characteristics/measurments for water quality

(1) specific measurements (2) aggregate measurements

The single most important (aggregate) measurement we use

Turbidity

Units of turbidity

Nephelometric turbdity units (NTUs)

The “master variable” of water chemistry

pH

Hardness definition

Multivalent cations (Ca2+ and Mg2+)

Most common indicator microorganism used today

Total coliforms

Three criteria to regulate a drinking water contaminate

(1) Toxicity (2) Exposure/Occurence (3) Necessity

CCL

contaminant candidate list: known to occur in public drinking water but currently unregulated, every 5 years

CCL5

PFAS

UCMR

unregulated contaminant monitoring rule: 30 contaminants every 5 years, contaminants “in the news” and on CCL radar for public water systems to monitor

Year the SDWA was established

1974

SDWA

ensures safe TREATED drinking water for the public

Primary Standards

legally enforceable standards the apply to public water systems

MCL

the highest concentration that can be present in a treated drinking water

MCLG

highest concentration at which no adverse health effects occur, not enforceable

TT

an enforceable procedure used to control a contaminant, often a BAT (best available technology) is used

Two ways primary standards are established

(1) MCL

(2) TT

Secondary Standards

noneforceable guildines related to cosmetics

First Amendment to SDWA

1986, (1) required EPA to act faster, (2) disinfection and filtration, (3) limit use of lead in drinking water pipes, (4) establish groundwate well protection, (5) hazardous waste injections

Surface Water Treatment Rule

Required most systems to filter and disinfect drinking water from surface water sources

Second Amendment to SDWA

1996, established CCL and UCMR, the “People’s Amendment” requiring accessible annual water quality reports

Disinfectants and Disinfection By-product Rule

Reduce exposure to DBPs

Interim Enhanced Surface Water Treatment Rule

public water systems for more than 10k people, for surface water systems using direct filtration, water must be less than 0.3 NTU

Revised Lead and Copper Rule

corrosion control requirements at treatment plant, only rule that concerns water at the tap

Milawukee Cryptosproridium Outbreak (1993)

Second Amendment to SDWA followed this event