Water Treatment and Distribution Fundamentals

Vocabulary and regulatory requirements related to water treatment, disinfection, and distribution systems.

Best disinfectant against Cryptosporidium

Ozone

Langelier Index indication if pH > pHs

The water is scale forming

Product of softening high calcium bicarbonate water by ion exchange

Sodium Bicarbonate remains in the product water

Gate valve accessory

Bypass valve

Meter pit riser pipes spacing for frost protection

$1-2$ inches away from any wall of the meter box

Ball and Socket Joint

A type of pipe joint available in both bolted and boltless flexible pipe joint designs

Push on joint

A pipe joint that permits flexible pipe alignment, is inexpensive to manufacture, and is easy to assemble

PVC C-value

$$150+$$

Pinch valve

A valve particularly useful for throttling the flow of corrosive liquids

Water meter pit primary location

Cold climates

Polyethylene pipe

A type of pipe that fuel oil will permeate

Operating time calculation for softening

$39.6\,hr$ if treating $297000\,gallons$ at a flow rate of $125\,gpm$

P-Q curve

A curve showing the relationship between power and capacity in pump operation

Head Loss

Energy used by water when moving from point to point

Static Suction Lift

Difference in water placement

Power

Work done in a given time

Total Coliform MCL compliance threshold

No more than $5\%$ of samples are acceptable for systems collecting at least $40$ samples per month

Virus removal and/or inactivation requirement

At least $4$ log

Sampling points for organics (except THMS)

Entry points to the distribution system

Sampling points for natural radionuclides

Each entry point to the system

Continuous chlorine residual monitoring (SWTR)

Required where water enters the distribution system when population served is $> 3300$ people

Consumer Confidence Report posting requirement

Must be on a publicly accessible website if the system serves more than $100000$ people

Source water TOC compliance level

$< 2.0\,mg/L$ calculated quarterly as a running annual average

SWTR technology exclusion

The Surface water treatment rule does not specify chloramine disinfection

Tier 2 violation

A regulated organic contaminant concentration that exceeds the MCL, requiring public notification within $30$ days

Chlorinated organic compounds balance

Operators must balance regulations on amount with meeting disinfection limits

Enhanced coagulation exemption

Not required if the treated water quarterly running average TOC is less than $2.0\,mg/L$

Stage 1 DBPR MCL for TTHM

$$0.08\,mg/L$$

Safe Drinking Water Act public water system definition

A supply of piped water for human consumption with at least $15$ service connections, or serves $25$ or more persons $60$ or more days each year

Enhanced Coagulation factors

Source water total organic carbon and Alkalinity levels

Filter Backwash Recycle Rule scope

Applies to all sizes of systems

Total coliform rule

The rule that most directly guards against the presence of Escherichia coli

Coliform bacteria sample type

Grab sample

NA2S2O3

Chemical element used to remove chlorine from water

Inorganic metals analysis preservation

Water should be codified with concentrated nitric acid

Membrane filter coliform colony characteristics

Pink to dark red with a green metallic sheen

Dissolved solids unfit for human consumption

The first level is $4000\,mg/L$

Atomic Absorption Spectrophotometer

A special photometer used to analyze for heavy metals in water

MTF confirmed test culture media

green lactose bite broth

Brilliant Green Bile tubes

Used to confirm all positive samples in the presence absence test

pHs

pH saturation

pH

A measure of the hydrogen ion concentration presence in water

MTF method steps

Presumed, Confirmed, Completed tests

Conductivity

A measure of the ability of an aqueous solution to carry current

Carbon dioxide

Colorless, odorless, and naturally occurring in all water

Jar test

The most readily available method for testing coagulant effectiveness, used for years

Calcium carbonate saturation point factor

Primarily depends upon pH

Lime effect

Increases pH, Hardness, and Alkalinity

Polyphosphate

A chemical used for stabilization of potable water that is a bacterial nutrient

Hexametaphosphate

Chemical used for corrosion control that could cause wastewater discharge requirements to be exceeded

Lime for corrosion control

Commonly used because it can adjust both pH and Alkalinity

Tuberculation

Buildup of corrosion products or uncontrolled scale deposits that reduces pipeline capacity

Quicklime

Unslaked lime

Zinc

The metal most likely to corrode compared to tin and aluminum

Principal source of lead and copper

Corrosion of household plumbing

Lime adjustment advantages

Availability, Inexpensive, easy to feed

CaCO3

Chemical formula of calcium Carbonate

Molarity

The number of moles of solute per liter of solution

Percent by weight calculation first step

Determine the molecular weight

Normality

The number of equivalent weights of solute per liter of solution

Solution components

A solvent and a solute

Oxygen atoms in Ca(HCO3)2

$$6$$

Minimum distribution system disinfection residual

Not below $0.2\,mg/L$ for more than $4\,hours$ for populations $> 3300$

Action level of copper

$$1.3\,mg/L$$

Turbidity sampling points

Points where water enters the distribution system, including all filter effluents of a surface water treatment plant

SWTR disinfection residual location

Collected at the same location as coliform samples

MCL for HAA5

$$0.06\,mg/L$$

Benchmarking

Determining the lowest monthly average during a $12$ month monitoring of giardia and virus inactivation

MCLG of expected carcinogens

Zero

Optimal pH for Alum

$6.5$ to $7.2$ for the removal of particulate matter

Van der Waals force

Forces that pull particles together once destabilized in coagulation-flocculation

Common flocculation mistake

Excessive flocculation time

Ferric sulfate advantage

More dense floc compared to alum

Effect of low turbidity

The lower the turbidity, the more difficult it is to form proper floc

Jar test units

Milligrams per liter ($mg/L$)

Raw water characteristics for chemical selection

PH, Temperature, Alkalinity, TOC, and Color

Freezing point effect on coagulation

Slows the process by making floc settle slower and making water denser

Solution for enteric protozoans in effluent

Multi barrier approach: coagulation, Flocculation, Sedimentation, and Filtration

Short circuiting cause

Poor inlet baffling in a sedimentation basin

Sedimentation Cryptosporidium removal

Less than $0.5$-log

Dissolved air flotation

Particularly good for removing algae

Sludge layer

Develops as solids settle to the bottom of a sedimentation basin

Maximum weir loading

$10\,gpm/ft$ for light alum floc in solids contact basins

Rectangular sedimentation basin components

Baffle, Adjustable Weirs, Sludge Pump, Collector drive

SWTR C x T requirement

Surface water systems must maintain specified $C \times T$ values before reaching the first customer

Primary test for poor sedimentation

Test for turbidity

Lime sludge disposal restriction

Cannot be discharged to a sanitary sewer system because it might build up and block sewers

Riparian Doctrine

The rule of reasonable sharing of water

Absolute ownership

The rule that landowners can capture all the water under their land

Reasonable use

The rule that a landowner has the right to groundwater as long as it does not harm a neighbor

Appropriation-permit systems

Water rights based on priority of usage over the longest time

Algae control strategy

Control nutrients to prevent filter clogging

Nitrate long-term action

Manage watershed to prevent nitrates from entering the water system