Water Quality Guidelines and Standards Flashcards
Definition of water quality guidelines according to the Philippine Clean Water Act of 2004 or R.A. 9275
The level for a water constituent or numerical values of physical, chemical, biological, and bacteriological or radiological parameters which are used to classify water resources and their use, which does not result in significant health risk and which are not intended for direct enforcement but only for water quality management purposes, such as determining time trends, evaluating stages of deterioration or enhancement of the water quality, and as basis for taking positive action in preventing, controlling or abating water pollution.
Basis of water quality guidelines
human consumption and usual domestic consumption
It is any legal restriction or limitation on quantities, rates and/or concentrations or any combinations thereof, of physical, chemical or biological parameters of effluent which a person or point source if allowed to discharge into a body of water or land
Effluent Standard
Characteristics of Water Quality Standards
- Based on water quality guideline values
- Take into account a variety of geographical, socio-economic, dietary and other conditions affecting potential exposure
- Expressed in terms of microbiological, physical, chemical, and radiological characteristics of water
What was updated from the 2007 PNSDW?
need for water quality standards during emergency situations
Rationale of PNSDW 2017
- Access to safe drinking water for the protection and promotion of public health
- Limits are set to minimize risk and prevalent deleterious effects
Basis of PNSDW 2017
WHO, US EPA and 2011 Australian Drinking-Water Guidelines
Classifications of drinking-water quality parameters
- Mandatory Parameters
- Primary Parameters
- Secondary Parameters
- Emergency Drinking-water parameters
[Classifications of drinking-water quality parameters]
site-specific wherein it concerns chemical impurities directly affecting health through acute or chronic exposure (i.e.: Benzene, Radon, Pesticides (Atrazine, Endrin))
Primary Parameters
*may be adopted as enforceable parameters
[Classifications of drinking-water quality parameters]
These are legally enforceable and concerns those that directly affect health through acute or chronic exposure and/or will render the water unacceptable for drinking
Mandatory Parameters
What are the viable indicators for general quality and stability of water supply?
- Total Coliform
- Arsenic
- Cadmiun
- Lead
- Nitrate
- Apparent Color
- pH
- Total Dissolved Solids
- Turbidity
- Disinfectant Residual
[Classifications of drinking-water quality parameters]
• Residual chlorine: 0.5-1.5 mg/L
• E. coli: absent per 100 ml sample
Emergency Drinking-water parameters
[Classifications of drinking-water quality parameters]
These indicate the possible presence of other contaminants and exceed tolerable values based on local monitoring data
Mandatory Parameters
• Have wide spatial distribution across the Philippines
[Classifications of drinking-water quality parameters]
Parameters which render the water unacceptable for drinking which include operational parameters which affect efficiency of treatment processes
Secondary Parameters
*involve iron, hardness, odor
Microbiological characteristics are typically expressed in terms of
concentration of particular species of bacteria
*detect and enumerate indicator bacteria
These are the most common indicator bacteria
coliforms
Water is tested for these kinds of coliforms
total and fecal/thermotolerant (i.e.: E. coli)
What does E.coli in chlorinated water (even at low concentrations) indicate?
Chlorination system failure
What does e.coli in tap water at some distance from treatment works indicate?
introduction of contamination at some point in the distribution system
T or F: nearly all bacteria in untreated water sample will be of no health significance and their presence is quite irrelevant except for fecal bacteria
true
conditions where fecal bacteria die off faster
warm water
sunlight
Three methods of microbiological tests according to the 2017 PNSDW
- Most probable number or multiple tube method
- Membrane filtration technique
- Enzyme substrate technique
[Microbiological tests]
In membrane filtration technique, water is filtered through what
cellulose membranes having a pore size of only 0.45 um which retains all bacteria and placed in a nutrient medium after and incubated
[Microbiological tests]
unit of concentration in membrane filtration technique
bacteria/100 ml
[Microbiological tests]
different volumes water sample are mixed with a number of tubes of nutrient medium and incubated for 24 hours at 37°C for total coliforms and 44°C for fecal coliforms
Multiple tube method
[Microbiological tests]
What confirms presence of coliform bacteria in multiple tube method?
Production of acid (purple to yellow) and gas
[Microbiological tests]
By observing the number of positive reactions in multiple tube method, what is derived?
MPN of coliform bacteria
[Microbiological tests]
This is used to test for presence or absence of coliform bacteria
Enzyme Substrate technique
*reagent is added to sample and incubated for 18 hours at 37C
[Microbiological tests]
Results of enzyme substrate technique
(1) colorless=negative;
(2) yellow=total coliforms;
(3) yellow/fluorescent = E. coli
Procedure for quantification in enzyme substrate technique
- Mix reagents with the sample, pour into incubation tray
- Seal, incubate
- Count: (1) yellow cells=total coliforms; (2) fluorescent=E. coli
enzyme and substrate present intotal coliforms
Chromogenic substrates:
(orthonitrophenyl-ß-D-galactopyranoside [ONPG] or chlorophenol red-ß-D-galactopyranoside
[CPRG])
Enzyme: ß-D-galactosidase
organism which uses fluorogenic substrate (4-
methylumbelliferyl- ß-D-glucuronide [MUG]) in enzyme substrate technique
E.coli
enzyme: ß-glucuronidase
indication: Presence of fluorescence (366nm UV
light) → MPN
Indication of total coliform in enzyme substrate technique
Production of a color change (ONPG:yellow/
CPRG:red) after incubation at 24- 28h → CFU/100mL
[Microbiological Standards]
Standard values for heterotrophic plate count
<500 CFU/ml
[Microbiological Standards]
Standard values for fecal coliform or E.coli and total coliform
MTFT: <1.1 MPN/100mL
MFT: <1 colony/100mL
EST: Absent or <1 MPN/100mL
*US EPA: 0
Source and mode of supply for sampling of drinking water supply systems
Level I, II, III, Buildings, Food establishments, Ice plants
Minimum frequency of sampling for TC and E. coli
- TC: 95% of samples are TC negative
2. Thermotolerant: no samples should test positive
Point of compliance in frequency of sampling for drinking water supply systems???
Point source, communal faucet, consumer’s tap
These are qualities of water which may lead to unpleasant taste, odor, appearance or other property to discourage use
Physical and Chemical characteristics
*health hazardous pollutants
Mandatory Physical and Chemical Parameters with Standard values
Arsenic: 0.01 mg/L Cadmium: 0.003 mg/L Lead: 0.01 mg/L Nitrate: 50 mg/L Apparent Color: 10 color units Turbidity: 5 NTU pH: 6.5-8.5 Total Dissolved Solids: 600 mg/L Disinfectant Residual • Chlorine Dioxide: 0.2-0.4 mg/L (more harmful) • Chlorine: 0.3-1.5 mg/L
Sources of arsenic
naturally occuring
Source of cadmium
Impurity of zinc coating of galvanized pipes and solders and metal fittings
Source of turbidity
from suspended matter
source of apparent color
Organic materials, iron and manganese, suspended matter
source of lead
Plumbing systems containing lead pipes, solder, fittings, or the
service connections to
the homes
source of nitrate
Leaching or runoff from agricultural land or contamination from human or animal waste
sources of total dissolved solids
Natural sources, sewage, urban runoff and industrial wastewater
Difference of true color and apparent color
true: when turbidity is removed
apparent: without turbidity removal
Acidity observed in wastewater
mineral acidity
REQUIREMENTS FOR THE OPERATION OF INDUSTRIAL ESTABLISHMENTS
- Adequate potable water supply provided to all employees
- Standard drinking water facilities shall be readily accessible to all employees (1 facility for every 50 employees)
- Where a local or city waterworks system exists, the industrial establishment shall utilize water from the system or from its own water supply that complies with the PNSDW
fundamental characteristics of wastewater/sewage
- Suspended solids
- Oxygen demand
- Pathogenic organisms
- Toxic chemicals
How are suspended solids determined?
Determined by filtering wastewater and retaining the solids on a filter paper which is oven-dried and weighed
This is the amount of oxygen required to oxidize organic chemicals which is a GROSS and INDIRECT measure of total organic load contained in sewage
oxygen demand
*COD/BOD
This is the measure of the amount of chemicals (usually organics) that consume dissolved oxygen which is measured by boiling the sewage with an acid dichromate
solution
COD
- Organics are converted to carbon dioxide and water
- COD = 1.5 x BOD
This is the amount of oxygen consumed by bacteria that are decomposing organic matter which is measured by allowing the sample to stand at 20°C for five days and calculating the amount of oxygen used up during the oxidation of the organics by bacteria
BOD
[CLASSIFICATIONS OF WATER SUPPLY]
These are intended for waters having uninhabited watersheds and/or otherwise declared as protected areas which require only approved disinfection to meet latest PNSDW (2017)
Class AA (Public Water Supply Class I)
[CLASSIFICATIONS OF WATER SUPPLY]
Intended for sources of water supply requiring conventional treatment (coagulation and
flocculation, sedimentation, filtration, disinfection) to meet PNSDW
Class A (Public Water Supply Class II)
Water class intended for primary contact recreation (bathing, swimming, etc.)
Class B (Recreational Water Class I)
Intended for fishery water for the growth and propagation of fish and other aquatic sources; Boating, fishing, etc.; Agriculture, irrigation, livestock watering
Class C (Recreational Water Class II)
Water class intended for industrial water supply for manufacturing purposes and navigation and other similar uses
Class D
They enforce provisions of PNSDW and develop and implement DWQ surveillance program and establish local DW monitoring committees
LGUs
*also advocate for importance of DWQ standards and its health effects
Gov agency which ensure compliance of all drinking-water service providers; provide technical assistance to local government units, DW service providers and to the general public and accredit water laboratories, certify training providers and
water sampling personnel
DOH
They comply with provisions, secure accreditation and implement quality control
water laboratory
- Comply with provisions
- Develop or implement a water safety plan
- Institute corrective actions for any unsatisfactory results of water sampling/testing
- Submit samples to accredited labs in a timely manner
- Submit results to local health authority
- Educate consumers on the safety of drinking-water
Drinking Water Service Provider or Building Operators
