Pool plant operator

What process identifies risks in pool use?

Risk Assessment process

List 5 steps of risk assessment

Identify hazards → Who may be harmed → Evaluate risks → Record → Review

What is NOP?

Normal Operating Procedures

What is EAP?

Emergency Action Plan

Risk assessment inputs

O&M manuals, Codes, SDS

Risk assessment outputs

Procedures, PTW, Method statements

Do employees have duties?

Yes

David Lloyd failure cause

No pump re-priming procedure

Essex burn chemical

Sodium hypochlorite

Suction at drains fatal?

Yes

What is SDS?

Safety Data Sheet

Who must cooperate (H&S law)?

All employers

Example emergencies

Fire, gas, chemical spill, contamination

NOP describes?

Daily operation

EAP describes?

Emergency situations

3 pollution types

Physical, Chemical, Biological

Main pollution source

Bathers

Crypto type

Parasitic protozoa

Crypto survival

10.6 days

Crypto exclusion

14 days

Crypto abbreviation

Crypto

Legionella affects

Lungs

Legionella temp

25–45°C

Pool lab testing

Monthly

Spa legionella

Quarterly

Hydrotherapy testing

Weekly

Higher pollution pool

Spa

Pollution location

Top 150mm (70–80%)

Biological pollution

Pathogens

Chemical pollution examples

Sweat, urine

Physical pollution examples

Hair, dust

Why urea is problem

Creates chloramines

Total chlorine

Free + Combined

Combined chlorine

Total - Free

Ideal free chlorine

0.75–1.00 mg/l

Max combined chlorine

Breakpoint chlorination

Oxidation of chloramines

High pH effect

Reduces chlorine effectiveness

Ideal pH

7.0–7.2

Total alkalinity role

Buffers pH

Ideal alkalinity

80–200 mg/l

Calcium hardness

80–200 mg/l

TDS limit

1000 ppm above source

Water balance -1.20

Corrosive water

Chemical reduces chlorine

Sodium thiosulphate

DPD1 purpose

Detect bleaching effect

Free chlorine definition

Active disinfectant

Combined chlorine

Used chlorine (chloramines)

Total chlorine

Sum of both

High combined chlorine symptoms

Smell, irritation

pH scale

0–14

Low pH effect

Corrosive

High pH effect

Poor disinfection

Raise pH chemical

Sodium carbonate

Lower pH chemical

CO2 / Sodium bisulphate

Correct treatment order

Pumping → Coagulant → Filtration → Heating → Acid dosing

Pump vs filter

Pump upstream

Upstream pipe

Suction

Downstream pipe

Pressure

Filtration rate

10–25 m³/m²/hr

Filtration formula

Flow ÷ Area

Backwash rate

30 m³/m²/hr

Backwash purpose

Fluidise sand

Filter gauges purpose

Pressure difference

Filter media change

5–10 years

PAC dosing point

Before filters

PAC dose (125 m³/hr)

12.5 ml/hr

Slug dosing alum

Not recommended

Turnover time

Time to circulate full volume

Flow rate

Water movement speed

Flow unit

m³/h

Turnover formula

Volume ÷ Flow

Turnover (50m³,100m³/h)

30 minutes

Spa turnover

6 minutes

General pool turnover

2.5–3 hours

Diving pool turnover

4–8 hours

Max heating rate

0.25°C/hour

Max emptying rate

750 mm/day

Dosing system inspection

Weekly

Dew point (30°C,60%)

21°C

Stress corrosion cause

Condensation + chemicals

Grille checks

Daily

Backwash trigger

Pressure increase

Backwash duration

Until clear (3–5 min)

Air scour

Breaks sand clumps

Channelling

Water bypasses filter

Filter freeboard

Space for expansion

Laterals

Collect filtered water

Mud-balling

Clumped dirty sand

Calcification

Hardened sand

Multiport valve

Controls filter modes

Do not turn valve under pressure

Can damage system

Waste mode

Bypass filter to drain

Recirculate mode

Bypass filter loop

What is coagulant

Clumps particles