Cpcprf2023a - Collect and Store Roof Water

CONSTRUCTION, PLUMBING AND SERVICE

INTEGRATED FRAMEWORK

TRAINING PACKAGE

CPCPRF2023A

COLLECT AND STORE ROOF WATER

LEARNING GUIDE ii © Commonwealth of Australia 2015 CPCPRF2023A - COLLECT AND STORE ROOF WATER

ACKNOWLEDGEMENTS

National Plumbing Services Training Advisory Group

Plumbing Industry Commission Victoria

Construction and Property Services Industry Skills Council PO Box 151 Belconnen ACT 2616 Tel: 02 6253 0002 www.cpsisc.com.au

This work is copyright, but permission is given to trainers and teachers to make copies and contextualise the resources for use within their own training organisation or in a workplace where training is being conducted. This permission does not extend to making copies for use outside the immediate training environment for which they are made, or the making of copies for hire or resale to third parties. This work was first published in 2004 with the assistance of funding provided by the Commonwealth Government through the Australian National Training Authority (ANTA). The 2015 publication has been updated to reflect changes to the national units of competency.

The views expressed in this work do not necessarily represent the views of the Commonwealth of Australia or CPSISC. In addition, the Commonwealth of Australia and CPSISC do not give warranty or accept any legal liability in relation to the content of this work.

The website addresses and other contact information provided in this publication were compiled in good faith and were correct at the time of printing.

The updating of these resources was completed by:

National Plumbing and Services Training Advisory Group, with funding and support provided by the Construction and Property Services Industry Skills Council (CPSISC):

This guide was developed in consultation with representatives of the Plumbing Industry by NPSTAG and CPSISC to support the implementation of the CPC08 Construction, Plumbing and Services Training Package.

Contents What is this resource about?...... 1 How do I use this resource?...... 1 Flexible Delivery...... 1 What do I have to do?...... 1 Unit Descriptor...... 2 Element...... 2 Performance Criteria...... 2 Required knowledge...... 3 How will I be assessed?...... 4 Are there any pre-requisites?...... 4 What other resources will I need?...... 5 Texts or References...... 5 Web sites...... 5 Video or audio cassettes...... 5 Safety...... 6 Workplace environment and safety...... 6 Introduction...... 7 Identify water storage system requirements...... 9 Obtain plans or specifications and any special instructions...... 9 Plans and specifications...... 10 Manufacturers’ specifications...... 10 Site inspection...... 10 Authorities...... 11 Follow WHS requirements...... 12 Workplace health and safety plan...... 12 Follow quality assurance requirements...... 14 Work place operations and procedures...... 14 Determine site’s rainfall...... 15 Determine roof catchment area...... 16

iv © Commonwealth of Australia 2015 CPCPRF2023A - COLLECT AND STORE ROOF WATER

Actual roof area...... 16 Effective roof area...... 17 Annual rainfall catchment...... 17 Determine water consumption requirements...... 18 Determine water storage requirements...... 19 Calculate requirements for tank(s), gutters, downpipes...... 20 Tanks...... 20 Gutters and downpipes...... 21 Plan and prepare for installation...... 22 Order materials...... 22 Plan work with others...... 22 Check materials...... 23 Install storage system...... 23 Gravity feed systems...... 25 Static head and head pressure...... 25 Below ground tanks...... 26 Tools and equipment...... 27 Locating tanks...... 28 Clean up materials...... 33 Clean tools and equipment...... 34 Complete documentation...... 35 Assessment checklist...... 45

What is this resource about?

Welcome to CPCPRF2023A – Collect and store roof water. This resource will help you gain the skills and knowledge necessary to demonstrate competence in this unit.

How do I use this resource?

This resource is divided into four main sections: CPCPRF2023A:  A learning unit, which contains background information on collect and store roof water  Worksheets, which prepare you for the practical examination  Practical application, which allows you to experience the collection and storage of roof water  Assessment materials, which help you to demonstrate competency.

To complete this unit of competence you will need to:  read the information contained in the learning unit  complete the worksheets as instructed  have your answers checked by your trainer or supervisor  work with your trainer or supervisor to practice working safely on roofs  read the assessment checklist together with the assessment sheets  complete the assessment

Learning Resources are not intended to be the only source of information nor are they intended to be an exhaustive form of instruction.

Flexible Delivery

The Trainer or Supervisor may adapt and deliver this Learning Resource to suit people from diverse backgrounds to meet equity principles and conform to Legislative policies.

What do I have to do?

To demonstrate competence in this unit you will be required to show the level of skills and knowledge for each of the elements involved to work safely on roofs:  Identify water storage system requirements  Plan and prepare for installation  Install storage system  Cleaning up.

If you are unsure of the meaning of these elements, you should read the performance criteria on the following page.

CPCPRF2023A Collect and store roof water Unit Descriptor This unit of competency specifies the outcomes required to determine storage requirements and to plan, prepare and install storage tanks and related piping for the collection and storage of roof water. The unit requires the installation of water storage tanks of at least 1000 litres capacity.

Element Performance Criteria Elements define the essential Performance criteria describe the required performance needed to outcomes of a unit of demonstrate achievement of the element. Where bold italicised competency. text is used, further information is detailed in the required skills and knowledge and/or the range statement. Assessment of performance is to be consistent with the evidence guide. 1 Identify water storage 1.1 Plans, specifications and any special instructions are obtained system requirements 1.2 Work health and safety (WHS) and environmental requirements associated with collecting and storing roof water are adhered to throughout the work 1.3 Quality assurance requirements for company operations are identified and adhered to 1.4 Site's annual rainfall is determined from meteorological or other relevant data 1.5 Roof catchment area is determined from plans or site inspection 1.6 Water consumption requirements for the installation are determined 1.7 Total water storage requirements for the installation are determined 1.8 Criteria for storage tanks, gutters, downpipes and other system components are determined according to relevant Australian standard and other information 2 Plan and prepare for 2.1 Required materials are identified, ordered and installation collected according to workplace procedures 2.2 Work is planned in conjunction with others involved in or affected by the work 2.3 Materials are checked for compliance with docket and order form and for acceptable condition, and faults are reported 2.4 Work area and materials are prepared to support efficient installation 2.5 Sustainability principles and concepts are observed when preparing for and undertaking work process

2 © Commonwealth of Australia 2015 CPCPRF2023A - COLLECT AND STORE ROOF WATER

3 Install storage system 3.1 Set out complies with design drawings or instructions 3.2 Preparatory work, including installation of tank stand or standing, is carried out to specification without damage to surrounding structures or existing services 3.3 System is installed according to job specification and statutory and regulatory authorities’ requirements 4 Clean up 4.1 Work area is cleared and materials disposed of, reused or recycled according to legislation, regulations, codes of practice and job specification 4.2 Tools and equipment are cleaned, checked, maintained and stored according to manufacturer recommendations and workplace procedures 4.3 Documentation is completed according to workplace requirements.

Required knowledge Required knowledge for this unit is:  job safety analysis (JSA) and safe work method statements (SWMS)  procedures for commissioning water storage tanks for use  processes for accessing information and for calculating material requirements  properties of water, including:  effect of gravity and atmospheric pressure  procedures for maintaining water quality  sources of contamination and impurities  regulations and requirements pertaining to collecting and storing drinking water and non drinking water  relevant statutory requirements related to collecting and storing roof water  SI system of measurements  water storage installation processes workplace and equipment safety requirements

An up to date version of the ‘Unit Descriptor’ may be located on the Australian Government web site training.gov.au http://training.gov.au/Search/Training? searchTitleOrCode=&nrtSearchSubmit=Search&includeSupersededData=true&includeSupersededData=f alse&homePage=true&javaScriptEnabled=true&typeAllTrainingComponents=true

How will I be assessed?

Your trainer or supervisor will decide with you how you will be assessed. Your assessment activity may include completion of the participant worksheet and practical task selected by your trainer or supervisor. Your assessment should allow you to demonstrate all the skills and knowledge required to collect and store roof water.

This unit may be assessed in conjunction with other units of competence. Your trainer or supervisor will tell you if you are to be assessed in this way.

Are there any pre-requisites?

Prior to commencing in CPCPRF2023A - Collect and store roof water you must have successfully completed the following pre-requisites:  CPCPCM2043A - Carry out WHS requirements

It is also recommended that prior to commencing CPCPRF2023A - Collect and store roof water you should have successfully completed the following competencies:  CPCPCM2039A - Carry out interactive workplace communications  CPCPCM2040A - Read plans and calculate plumbing quantities  CPCPCM2046A – Use plumbing hand and power tools  CPCPCM2047A - Carry out levelling.

Project work may also group pre-requisite or co-requisite competencies together to carry out such projects. It is recommended that the following competencies are grouped with this unit of competency:

CPCPRF3022A Fabricate and install roof drainage components.

What other resources will I need?

To assist you the following resources have been suggested and should be available to you to do this competency:

Texts / References

 AS/NZS3500 – Plumbing and drainage  SAA HB 114: Guidelines for the design of eaves and box gutters.  AS/NZS2179 - “Specifications for rainwater goods, accessories and fasteners”  AS2180 – “Metal rainwater goods – selection and installation”  AS3855 – “Suitability of plumbing and water distribution systems products for contact with potable water”;  Plumbing code of Australia  State or Territory regulations may override this Learning Resource.

Web sites

Video/audio cassettes

Safety Workplace Health and Safety (WHS) requirements need to be observed in accordance with legislation. You need to know the WHS laws governing your job. Revision of CPCPCM2043A – Carry out WHS requirements, before commencing this unit is advisable. In any work situation you reduce the risk of injury to yourself and others by using appropriate personal protective equipment (PPE). The types of PPE that you will need include: Overalls – used for the protection of the installer when working in different conditions. Boots – it is recommended that soft soled footwear is worn while working on roofs, as deep grooved footwear pick up small stones and debris that might damage or scratch the roof sheets. Safety glasses or goggles to protect the eyes from injury when cutting the sheets with a power saw

Ear plugs or muffs to protect the installer’s hearing from excessive noise. Dust masks or respirators to protect the user from breathing in dust or fine particles when cutting the sheets with a power saw. Gloves, for the protection of the installer’s hands when working with different types of pipes, tools and equipment.

Workplace environment and safety

Handling of materials Manual lifting and handling techniques must always be followed according to WHS requirements. You should move materials into position by hand where possible. Excessive manual handling should be avoided and cranes and other mechanical lifting devices should be employed when necessary. Limited height scaffolds Operators must ensure they are familiar with all operating procedures detailed and elevating work by manufacturers in the elevated working platforms operators’ manual. platforms (EWP) Personal protective equipment must be worn at all times by the person working in the basket of the EWP. This consists of safety harness, safety helmets, rubber soled shoes, safety vests and suitable clothing.

Introduction

This unit specifies the competency required to determine storage requirements and to plan, prepare and install storage tanks and related piping for roof water collection systems, for the collection of roof water.

You will be required to:

 Identify water storage system requirements

 Plan and prepare for installation

 Install storage system

 Clean up

In isolated country houses and some rural communities roof water has long been source of water for drinking and use. Increasingly however, rainwater tanks are being installed to supplement the reticulated supply by providing water for gardens, swimming pools, toilet cisterns and some other indoor applications.

Definition AS/NZS 3500.0 - Drinking (Potable) water – water which is suitable for human consumption, food preparation, utensil washing and oral hygiene.

The factors that influence the design of a roof water collection and storage include:

 The intended use of the water

o Drinking only

o General house usage

o Outdoor usage only

o All or a combination of the above

 The amount of water required

o Dependant on the intended use, and the number of consumers

 The available rainfall including

o Quantity and distribution

 The available roof area to capture the rainfall

 The available area for tank location dependent on the

o Land size and

o Terrain

o Tank to be above or below ground

 The tank materials

Identify water storage system requirements

Obtain plans or specifications and any special instructions

Clients may have quite different requirements for the collection and storage of roof water so it is important that these are identified. Before you begin installing a storage and collection system you need to obtain the plans and specifications from the local authorities. Gathering this information will help you to make informed decisions about the nature of the job and how to plan and sequence the entire process. Some of this information may be available from your job supervisor. Also, before beginning, work notices may need to obtained and submitted to the relevant authorities.

The table below shows some of the information sources you will use and the type of information each source can provide you with.

Source of information The information you can get

Plans or specification Location and details of installation

Site inspection Site layout and access Hazard identification Specific measurements

Authorities Work Permits Regulations, standards, codes, guidelines Service location

Manufacturers Material specifications and installation requirements

Company's quality Standards and procedures assurance

Weather bureau Atmospheric exposure conditions. Forecasts/warnings of bad weather.

Plans and specifications

Plans provide the following information:  plan view of the building outline and its distance from boundaries, roof outline, location of tank, gutters, downpipes and other rainwater goods  measurements of roof dimensions  elevation and section views showing roof details and level differences between gutters and tanks From this information, you will be able to calculate the catchment area and pipe to connect downpipes to the tank.

NOTE: A review of CPCPCM2040A - Read plans and calculate plumbing quantities will assist this process.

Specifications, which need to be read thoroughly and complied with, may state:  the tanks  capacity or dimensions  material  tank support requirements  profile and colour of rainwater goods  a statement about who is responsible for undertaking particular parts of the work, eg preparing support.

Manufacturers’ specifications

Most manufacturers have manuals or leaflet information to help you with product selection, installation procedures, care and handling instructions. These specifications should be followed or your warranty may be voided.

Site inspection

Although plans and specifications provide most of the information you require for an installation, a visit to the workplace at the planning stage will give you a clearer visualisation of the layout of the building and the site. While you are on site you should do the following.  Undertake a hazard identification.  Determine requirements not identified in the plans and specifications with client.  Check physical layout of the site that may affect access.  Make final check of measurements.  Confer with site foreman and other tradespersons you may need to cooperate with.

Authorities

Local Government Local governments control the building process, being responsible for the approval of development and building applications. Depending on your location approval may be required for installing a tank particularly if there is an existing reticulated supply. Other matters they may require are:  Clearances from boundaries  Approval of tanks  Stormwater provision  Protection of structures  Provision of water for bush fire fighting Standards Council inspectors will rely on building codes and standards for approving installations. These documents provide guidance to installers of minimum requirements.

Service Providers Service providers may also have requirements relating to installation based on standards, codes or guidelines. Again this is most likely if there is an existing reticulated supply. They can also provide information relating to the location of services and procedures if connection to, interruption or relocation is necessary. For small tanks it is probably unlikely but becomes more possible for larger in ground installations. Service providers include:  Electrical  Telecommunications  Gas  Water  Waste  Stormwater  Roads

Work Safety Work safety plays a major role in the construction industry and there are many regulations and codes relating to roofing practices. This will be dealt with below.

Follow WHS requirements

The installation of a roof water collection and storage system may present a variety of WHS situations. The units CPCPCM2043A Carry out WHS Requirements and CPCPCM2055A Work Safely on Roofs address the principles to be applied in this situation. Both these units should be referred to in the context of this unit.

Workplace health and safety plan

All work requires the development of a Workplace Health and Safety Plan. This plan will enable you to identify problems and manage the problems to ensure a safe workplace.

The steps involved and issues to cover include:  identifying the hazards involved  assessing the risks  controlling the risks.

Identifying the hazards involved

The hazards that you might come across include those associated with roofing and handling large, heavy objects as well as possibly those associated with excavation. Listed below are some of the more dangerous problems you will be faced with.  Working at height.  Electrical hazards.  Handling large and heavy materials.  Excavation.  Live load support.

Assessing the risks

Your ability to effectively assess the risks on the job will ensure your complete safety.

The risks may include:  falls from the perimeter of roofs  falls from ladders  electric shock  back or shoulder strains  crushing from soil collapse  falling into excavations

Controlling the risks

There are many tasks that you will need to consider in order to minimise the risks to your safety.  fall protection around the perimeter of roofs (scaffolding, guard rails)  fall arrest system (harness)  personal protective equipment  moving materials mechanically (hiring a crane)  positioning materials carefully to ensure the load is properly distributed  making fast the materials stored  ensuring safe access and egress  ensuring electrical safety  postponing work in bad weather.  restricting access to hazardous areas  shoring excavations.

Follow quality assurance requirements

Many companies have a policy for assuring quality to the customer. This policy is designed to control the processes used within the company, record keeping, quality of materials used and the way the work is done. You need to be aware of your company’s particular quality assurance requirements.

(NOTE: The WHS policy forms an important subset of this larger management plan.)

A continuous improvement process should be employed for the update of quality assurance provisions as the strengths and weaknesses of the policy are revealed over a period of time.

Quality assurance requirements may include:  workplace operations and procedures  workplace health and safety plan  quality of materials  control of handling procedures  use and maintenance of equipment  attention to specifications  provision of training specific to the type of work  details of warranty provided to client  recording and reporting requirements

Work place operations and procedures

Your own company may have procedures in place. These should be understood and followed. Other players concerned with the site may also have procedures and work place operations. These may include the builder, the maintenance contractor, and the materials supplier.

Determine site’s rainfall

When determining the capacity of rainwater tanks required for a home several factors need to be considered. One of the first is the amount of available rain, and its distribution throughout the year. The tanks must hold enough water so the home will have sufficient water to last through long periods of drought. In low rainfall areas the tanks will have to be larger than those in high rainfall areas.

The amount of annual rainfall for the area is determined from meteorological data and recorded in a unit of the SI system of measurement, ie. millimetres. This information can be obtained from:

 Your job supervisor

 The land owners records

 The Bureau of Meteorology

 AS/NZS 3500.3 - Appendix E

The figure below shows the approximate average rainfall in various regions of Australia. The map shows there is a vast difference in rainfall between different regions.

Average annual rainfall for Australia

Each region would have different rainwater tank requirements. Seasonal dry periods would also increase the need for greater storage capacity. It should also be noted that in recent times extended drought periods have become more common.

Determine roof catchment area

To calculate the yearly volume of rainwater which can be collected from a roof catchment area you must know the square meterage of the roof.

Actual roof area

Example

To calculate the roof area shown below, you will need to follow the procedure listed.

Roof plan of house

Divide the area into suitable squares or rectangles as shown. Area A = 5 m x 5 m Area B = 10 m x 10 m  Calculate the area of each separate square or rectangle.  Add them up to arrive at the total area. Area A: 5 x 5 = 25 m2 Area B: 10 x 10 = 100 m 2 Total Area: 125 m2

Effective roof area

This formula does not take into account loss due to splashing or wind velocity, so to calculate the catchment to a more reliable figure allow a thirty percent loss factor. Thirty percent is seen as a reasonable allowance for splash (wind loss).

Example

To find the effective roof area:

Total roof area (100%) = 125 m2.

Loss factor due to wind and splashing = 30%

Effective roof area = 70% of total roof area

125 m2 x 70 = 87.5 m2. 100

Annual rainfall catchment

Example

In this example the annual rainfall on the roof is 650 mm (0.65 m) per year.

Remember that 1 m3 = 1000 LITRES

Rainfall on a roof area:

= roof area (m2) x rainfall (m) x 70% (spray wind allowance)

= 125 (roof area) x 0.65 (rainfall) x 70 (splash allowance) 100

= 81.25 x 70 100

= 56.875 m3.

But 1 m3 = 1000 litres

So 56.875 m3 x 1000 litres

= 56,875 litres

NOTE: Remember this is a yearly average figure and does not account for seasonal variation and extended drought periods.

Determine water consumption requirements

Its intended use, and the number of users determine water consumption requirements. It may be required for:

 Drinking only

 General house usage

 Outdoor usage only

 All or a combination of the above

Obviously there is significant variation between the different possibilities. Where roof water is a supplement to other supplies such as reticulated supply, dams or bores requirements are greatly reduced.

Another factor that can significantly affect consumption is the water conservation culture of the household. People that have grown up with “unrestricted” supply may need to adjust their behaviour when relying on tank water.

The table below shows average daily rate of water consumption in an isolated domestic supply and how this increases with the addition of more people.

No of House with septic system House without septic system persons (litres per day) (litres per day)

1 200 140

2 270 200

3 320 250

4 340 270

5 360 300

6 380 320

7 430 360

8 450 380

In some cases, eg clothes or dishwashing, the same water is used by more than one person. It takes as much water to wash for one person as it does for three or four.

The table above shows that three people, in a household with a septic system, use only 320 litres per day (not 3 x 200) litres.

Determine water storage requirements

To determine how much water needs to be stored you need to know how long water needs to be stored. This is a figure that represents the length of time that can be expected without significant rain. In other words, if your tank is full and the rain stops, how long will it last.

To calculate the capacity of a storage tank needed for a household, multiply the daily rate of water consumption by the number of months’ storage (in days), that must be catered for.

Example

Using the table above calculate the water storage requirements for three months for four people in a Victorian household with septic system.

Size of tank required (litres) = Daily rate (litres) x Minimum storage days

Daily rate = 340 litres / day

Minimum storage days = 3 mths x 30 days

= 90 days

Size of tank required = 30,600 litres

This number represents the ideal situation of the tank being full the day the rain stops. If we take an average situation of the tank being half full, we must introduce a safety factor of two.

Size of tank required = 30,600 x 2

= 61,200 litres

This represents a tank approximately 6 metres in diameter and 2.1 metres high or 3 tanks 3.5 metres in diameter and 2.1 metres high. Installed, this takes up a considerable space and many people in this situation, where available, opt for large concrete storage tanks cast on site of 100,000 litre capacity either above or below ground.

Given that the minimum storage days are fixed there are two things that can affect the storage requirements.

1. Consumption can be reduced by changing habits to use less water or by introducing a supplementary supply like a dam or bore.

2. The size of the catchment area can reduce the safety factor by maying it more likely that the tank will be full when the dry period starts.

From the examples above we found that a 125 m2 roof in a 650 mm rainfall zone collected 56 875 litres of water per year. If the roof area could be doubled by perhaps connecting a shed roof to the tank collection with the same rainfall would be just over 110 000 litres. This would allow the safety factor to be reduced say 1.5 decreasing storage requirements to 46 000 litres.

It is obviously desirable to have a large storage capacity and catchment area. One advantage of going to larger tanks is that their cost per litre of storage goes down, but the difficulty in locating them and installation increases. In existing houses on small blocks with reticulated supplies it can be quite challenging to meet customer expectations.

Calculate requirements for tank(s), gutters, downpipes

Having determined the capacity of the tank/s from the specifications or the process above they have to be located. This depends on the available space and can be above or below ground. This affects the material they are made from. Metal tanks are suitable for above ground use only and depending on manufacturers specifications the other materials may be buried or partially buried.

See AS/NZS 3500.1 - Clause 2.3 – Storage Tank materials and Section 8 – Water Storage Tanks

Storage tanks for drinking water may be constructed from the following materials.

Galvanised steel – zinc coated z600 steel (prone to rusting) Metals Zincalume – silver coloured zinc/aluminium-coated steel (prone to rusting)

Aquaplate or Colorbond – coloured polymer-coated steel (lasts longer)

Copper and stainless steel – used for specialised applications (expensive) Older corrugated iron tanks were soldered while in later years silicone has been used to seal laps, rivets or spot welds.

Glass reinforced Only made on special request. No standard sizes available. plastic Very strong.

Reinforced concrete This material is being made redundant as other light weight materials have become available. Concrete is normally only used below ground, but most other materials can also be used in this situation.

Poly tanks Heavy duty polyethylene profiled or plain sided walls and base. Very light weight but very strong. Many standard sizes available. UV stabilised polyethylene.

Tanks and their associated pipework and fittings require SAA approval. Check with your local Authorities to establish their approval requirements.

Gutters and downpipes

The sizes of gutters and downpipes must be large enough to accommodate and convey heavy downpours of rain to the storage tanks without losing valuable water because of overflows from the gutters. You will normally be provided with this information, or they may already have been installed.

NOTE: CPCPRF3022A Fabricate and install roof drainage components addresses this topic in more detail.

Note Sizes of gutters and downpipes must be calculated in accordance with AS/NZS3500.3 Section 3 or SAAHB114

Worksheet Now go to the Worksheet and answer Questions 1 – 6.

Plan and prepare for installation

Order materials

Materials for the collection of drinking (potable) water must be carefully selected to avoid contamination of the water. Once you have calculated the storage requirements and have obtained the plans/specifications you can work out what materials are required. An order for the materials is then placed with a suitable supplier.

A copy of the materials order should be retained, so that on delivery it can be checked to match the quantities and types of goods ordered. The condition of the materials should also be checked before they are accepted.

A typical list may include:

 Tank support materials

 Tank

 Gate valve and fittings

 Stormwater pipe and fittings

 Gutter and fixings

 Downpipe and fixings

Plan work with others

You need to consider how the task you are about to commence affects others and plan with this in mind. Your company may have standard procedures that you will need to take into account. To assist in this process it might be helpful to make a list of the others involved in the work and contact those with whom you will need to cooperate. Ask the following questions:  What dangers may be caused by your work and who might be affected?  Will any others be affected by the safety measures that you propose to use?  Will the work interrupt the work or normal activities of others?  Will the delivery and storage of materials affect others?  Which trades will you need to complete their work before you can start?  Which trades need to work with you to complete the installation?  What deadlines must you meet to allow the project to meet planned schedules?

Check materials

On delivery you need to check the materials to ensure that they are of the standard required and have been delivered in acceptable condition. It is critical that you as the installer check the materials.  Correct tank has been delivered.  Ordered lengths of material are correct.  Fasteners as ordered.  Sealants as required.  All materials are compatible.

Prepare work area

The worksite must be prepared before you start the installation process. This may be as extensive as having earth works carried out to provide access and stability for tank installation or having powerlines isolated or relocated.

Other things to be considered are:

 WHS precautions should be in place before work progresses.

 Locating on-site storage for plant and material in convenient location for yourself and others.

 The work location is clean and tidy before, and after, work.  Before attempting the work take all precautions against damaging premises and fixtures.

Install storage system

Set out

The site conditions and the capacity and type of tank selected play a large part in determining where and how a tank will be installed. All the details collected in the preparation stages need to be followed during installation unless a problem is identified.

Factors to be checked include:  Footprint of the support structure.  Clearances from buildings and boundaries.  Effect of excavation on existing or proposed structures.  Level of tank inlet with respect to gutter.

Carry out preparation

Above ground tanks

All tank materials are suitable for above ground installation. They should be located as much as possible in shaded areas to prevent the water heating, which can also promote algae to grow. In relation to below ground tanks they have the following advantages. They:

 Don’t require major earthworks and are generally quicker to install.  Don’t have to withstand “earth pressures” and can be lighter and cheaper in construction.  Can be raised to provide limited gravity pressure.  Leaks can be easily detected.  Can be drained easily.

Their disadvantages include that they:

 Take up valuable space  Need to have suitable base constructed to support them.  Are exposed to weathering  May require tying down for times when the tank had little water

In all above ground situations it is important to ensure that the level of the inlet of the tank is the correct distance below the gutter for the collection system being used.

On ground

Concrete, fibreglass and polyethylene tanks can be installed on the ground. The ground should be firm, and an area slightly larger than the tank should be levelled, and cleared of hard materials that could puncture the tank. A layer of sand will protect the base of the tank and help distribute the load evenly.

On slab

A concrete slab may also be formed to support most tanks. It should be designed to support the required load. A plastic membrane may need to be placed on the slab under some products, or hardwood timber supports that allow air to circulate and remove moisture that might promote corrosion.

On stand

Stands can be used to both support an elevate tanks for additional pressure. Brick piers with timber bearers, joists and an open timber base must all be designed to carry the full tank load.

NOTE: 1 litre of water weighs 1 kilogram. 1 000 litres (1 m3) weighs 1 tonne

Above ground tank with gravity feed system

Gravity feed systems

Under normal circumstances a pump would be installed with the tank. Occasionally the water outlets are far enough below the level of the tank that they can work on pressure supplied from gravity. If this is the case the expense of a pump can be avoided. To determine if this is possible you need to be able to calculate the pressure due to the depth of water above the outlet.

Static head and head pressure

With a gravity feed system, the higher the storage tank level, the greater the outlet pressure will be.

The head pressure or static head is calculated by measuring vertical, the height of the water level above the outlet point.

For each 1 metre head of pressure, a pressure reading of approximately 10 kPa can be obtained (the actual pressure from 1 metre elevation is 9.81 kPa).

A tank storage with a water level of 30 metres above the outlet point will produce a pressure of approximately 300 kPa.

Outlet pressure

Below ground tanks

Below ground tanks need to be strong enough to withstand the pressures of being buried. Concrete is the normal material considered, but some plastic or fibreglass tanks may also be buried. Below ground tanks have the advantages that they:

 Take up less garden space  Keep water cool  Are well below the level of the gutter

Their disadvantages include:

 That leaks and problems are not obvious and they are susceptible to contamination through ground water  Can be damaged by tree roots  If access is not restricted there is a risk of people or animals drowning in the tank  Can be damaged by traffic  If ground is water charged, and the tank is low it may “float”.  Difficult to drain and clean

Tanks may be wholly or partially buried. To set out for an underground tank mark out and excavate a hole to suit the dimensions of the tank, with just enough allowance around the tank to enable the positioning to be adjusted when the tank is lowered into the hole. Once the required depth is achieved the ground should be levelled, and sharp objects removed. As with on ground tanks sand or fine grained fill may assist in this process.

When excavating care should be taken to avoid damaging existing services and damaging surrounding structures.

Worksheet

Now go to the Worksheet and answer Questions 7 – 13.

Install system

Storage tanks must be handled with care because there is usually no way of testing them for leaks until the rains have filled them up. The following preparations and installation procedures should be followed to avoid double handling or excessive shifting of the tanks.

Tools and equipment

Tools and equipment required to install a storage system to collect and store drinkable (potable) water may include the following. Particular jobs may require additional equipment.

Hand and power tools Spanners, pipe cutters, wrenches and drills to secure pipe work, pump and tank in position. Snips, shears and riveters to cut, shape and secure metal framework.

Excavation equipment Backhoe, shovel and crowbar to dig hole large enough for underground tank.

Ladders Correct length ladders to work on when securing tank in elevated position and entering or exiting tank excavation.

Measuring equipment Measuring tape and rule to measure setting out requirements and length of pipe work from tank to tap outlets.

Levelling equipment Laser and/or hand level to ensure tank is installed level.

Locating tanks

Lifting and handling procedures

Manual lifting and handling of heavy or bulky materials can cause back strains and other injuries. Manual lifting techniques like bending the knees and keeping the back straight should be employed, but whenever possible, lifting or load shifting equipment should be used. This must be in accordance with WHS requirements.

Lifting equipment may include the following. Hand trolleys Lifting or carrying equipment around work site.

Rollers Manipulate heavy equipment into place.

Forklifts If necessary to move large equipment into position.

Chain blocks To hoist material or equipment into elevated positions.

Jacks Help to hold heavy equipment in place while securing attachments.

Crane To lift tank, platform or accessories into position.

Safety equipment

Most tanks come prefabricated and just need locating. Some large capacity metal framed polyethylene tanks however come packaged and need fabrication on site.

This is a brief explanation of the installation process for a packaged tank. You should however follow the manufacturers’ instructions for the installation of their product as these may vary between different manufacturers.  Level base sand to required depth.  Mark out tank diameter on sand.  Erect the tank rings to required height.  Fit roof supporting structures.  Secure metal roofing sheets.  Secure poly liner.  Fit accessories: - access hatch - filter basket - outlet valve - overflow outlet.  Connect downpipes and drainage pipes into tank.  Fit outlet pipe work as per manufacturers’ specifications or local authorities’ regulations. Connection

Quality of water

Rainwater that has fallen on a roof catchment area surface is generally considered pure enough for drinking (potable) use. However, where a reticulated supply is also available authorities may recommend that this supply be used for drinking.

Rain can be collected from all metal based roof materials apart from lead or metal sheeting coated with lead based paints that can contaminate the water supply. Tiles, polycarbonate and fibre glass are also suitable.

The catchment area roofs must be kept clean and free from contamination. Roofs may become coated with dust, bird droppings, decayed vegetable matter (leaves, moss, weeds, etc) or other contaminants such as traffic or industrial pollution. Aerial spraying of insecticides and chemical fertilisers can also cause serious problems.

Tanks should all have tops to prevent evaporation, contamination and algal growth. If contaminants are likely to be collected on the water catchment surface, some form of diversion of the initial water (first flush device) run off may be necessary.

Screens may also be installed to remove leafs and tree matter. surfaces. Meshes also keep out mosquitoes and small animals.

Tanks have to be installed below the level of the gutter. Overhead connection is desirable but underground mains are quite often the only alternative. In this case a minimum 0.5 metre difference is required so that gutters don’t overflow during heavy rain. Downpipes and stormwater must also be watertight.

Rainwater collection methods

Overflow

The overflow from tanks should be discharged to an area where they won’t cause damage to structures or erosion.

Typical tank installation

Cleaning and disinfecting

Cleaning and disinfection

Under certain conditions, storage tanks are capable of harbouring bacteria which can cause serious illness or even death. When water in tanks becomes heated, it is sometimes possible for algae to be formed. Other contaminants as mentioned earlier in the resource may also contribute to this problem. Cleansing and disinfection is required to remove harmful bacteria before the tanks become operational.

Note Cleaning and disinfection of storage tanks is to be done in accordance with of AS/NZS 3500.1 -. Appendix H

Clean up work

Clean up materials

As with any job, you should allow time to clean up afterwards. Clean up includes:  cleaning surfaces of installed materials of swarf and debris  cleaning up the worksite  recycling of unused materials  properly disposing of waste  cleaning, maintaining and storing your tools and equipment.

Cleaning up the worksite is not just a matter of appearance. It also concerns safety and health issues. It is good work practice to clean up as you go and a sign of professionalism. Building sites are always short of space and build up of debris will only add to storage and health and safety issues. Roof plumbing work has the potential to generate rubbish and waste from a number of sources such as packaging, off-cuts or surplus material, removal of failed material or components, residue from cutting, drilling, riveting and other fabrication and installation processes.

Most large sites will have a site safety committee policy on cleaning up the worksite. Small sites such as single dwellings may not have a policy but the following principles apply for both.  The disposal areas for site debris should be identified at the site induction. If not find out from your supervisor.  Clean up as you go if possible, but at least on a daily and weekly basis and on completion of an installation.  Food and drink waste, wrappers and containers should be disposed of in the correct bin immediately after use, as build up attracts vermin and associated health risks.  Packaging debris should not be allowed to become a wind blown, tripping or other hazard. Dispose of it in the correct bin as soon as practicable or take it with you from the site.  Off-cuts and surplus material that may be used later in the job should be held in a safe storage area until required.  Off-cuts and surplus material that is not suitable for re-use should be disposed of in the correct bin at the end of each days work or sooner if practicable.  Swarf, trimmings, rivet tails, and other residue from fabrication, and installation procedures on roofs have the potential to cause severe corrosion and blockage problems. They must be carefully collected, removed from the roof and disposed of correctly according to site and company policy.  Do not use cupboards, empty rooms or corners to store rubbish and debris.  On completion of an installation check the whole of the work area. Remove materials to the store, tools and equipment to the correct location and rubbish and debris to the correct bins.  Sweep the area and dispose of sweepings.

Clean tools and equipment For efficient and safe installation tools need to be maintained and stored. Tools and equipment may be the responsibility of the site manager, contractor or others such as hire companies. You may be responsible for a tool kit and personal protective equipment (PPE).  Keep a running check on your toolkit and your PPE. Check, clean and maintain it at the end of each day.  Check and maintain company equipment on a regular basis according to company policy. Keep all equipment in good working order.  Clean and maintain hire equipment according to hire agreement and good practice.  Do not overload or abuse any tools plant or equipment.  On completion of installation collect, clean and maintain all tools and equipment and return to their storage locations.  Keep a running check on your tool kit and your PPE. Check, clean and maintain it at the end of each day.  Check and maintain company equipment on a regular basis according to company policy. Keep all equipment such as scaffolding, ladders and lifting machines in good working order.  Clean and maintain hire equipment according to hire agreement and good practice.  On completion of installation collect clean and maintain all tools and equipment.

Complete documentation On completion of work it may be necessary to report on what happened. In addition to time and materials this is another opportunity to express any concerns you might have with the effectiveness of safety and work procedures.

 Fill out WHS monitoring report  Complete checklist and store PPE.  Complete checklist and store toolkit.  Complete checklist and store company equipment.  Complete checklist and return hire equipment.

Name: ……………………………………………………

Worksheet

CPCPRF2023A – Collect and store roof water

The student should complete this worksheet before attempting the practical installation.

The worksheet may form part of the assessment and should be checked and signed off by your trainer or supervisor.

1. State two sources that an isolated farmhouse may depend on for its water supply.

2. Why are plans necessary?

3. State the minimum and maximum average rainfall zones in Australia.

4. Calculate the amount of rainwater which could be collected from the roof in the figure below, if the average annual rainfall is 950 mm allow for loss factor.

Area A =

Area B =

Area C =

TOTAL =

5. State the factors that effect minimum water storage requirements.

6. Calculate the water storage requirements for four people in a household without a septic system in your state or territory area.

7. Why is concrete being used less in tank making today?

8. How can water pressure from an above ground tank be increased?

9. Give two advantages of a below ground tank.

10. State two problems which can occur in a below ground tank.

11. The gravity feed system relies on the static head for its outlet pressure. The actual pressure from 1 metre of elevation is 9.81 KPa.

Calculate the pressure exerted from a storage tank with a water level of 25.6 metres above the outlet point.

12. State one reason for keeping an above ground water tank in a cool position.

13. Give three advantages of an above ground tank.

14. State two WHS requirements when installing a water tank.

15. Name four items of PPE that should be available and used as required.

16. Name three hand tools to be used when collecting and storing drinking (potable) water.

17. State three pieces of equipment which could be used for lifting or handling procedures.

18. What would be the water mass of a 5000 litre tank?

19. What types of contamination could be found on a roof?

20. Why must lead or metal sheeting coated with lead based paints must not be used on catchment area surfaces?

21. What type of roof materials makes the best rainwater collection areas?

22. How is water distributed to the house from a below ground tank?

23. Which accessory is used to prevent dead birds and vermin entering the tank?

24. Why should tanks be cleaned and disinfected?

Trainer or Supervisor’s Signature:…………………………………………………

Date of Completion:……………………………..

Name:……………………………………………………………

Practical application

Your trainer or supervisor will now work with you to demonstrate and explain safe working on roofs.

The following points will be covered:

Plans and specifications and any special instructions obtained

WHS requirements associated with the collection and storage of roof water, and the workplace environment, are adhered to throughout the work

Quality assurance requirements for company operations are identified and adhered to

Site’s annual rainfall is determined from meteorological or other relevant data

Roof catchment area is determined from plans or site inspection

Water consumption requirements for the installation is determined

Total water storage requirements for the installation is determined

Criteria for tank(s), gutters, downpipes and other system components are calculated in accordance with the relevant Australian Standard

Required materials are identified and ordered or collected in accordance with workplace procedures

Work is planned in conjunction with others involved in, or affected by, the work

Materials are checked for compliance with docket and order form and for acceptable condition

Work area and materials are prepared to support efficient installation

Set out complies with design drawings or instructions

Preparatory work, including the installation of tank stand or standing, is carried out to specification without damage to surrounding structures and or existing services

System is installed in accordance with job specification and regulatory authority’s requirements

Cleaning and disinfecting of system is carried out in accordance with the relevant Australian Standard

Work area is cleared and materials disposed of or recycled in accordance with State or Territory Legislation and workplace procedures

Tools and equipment are cleaned, checked, maintained and stored in accordance with manufacturers’ recommendations and workplace procedures

Documentation is completed in accordance with workplace requirements

Trainer or Supervisor’s Signature: …………………………………………………

Date of Completion: ………………………….

Assessment checklist

Criteria Yes No

Have the worksheets been successfully completed?

Has the practical task been completed?

Are the job specification and local authorities or utilities requirements available?

Trainer or Supervisor’s Signature:……………………………………………..

Date of Completion:…………………