• FAQs

    At Ireland Waste Water we often receive questions about our products and services. Here are a list of our most frequently asked questions. Please click on the buttons below to go to the appropriate section.

    Rainwater Harvesting FAQs

    What is Rainwater Harvesting?

    Rainwater harvesting is a way of saving the rainwater which would normally flow off your roof and down the drain, and instead use it as piped water to flush toilets and for watering the garden,vehicle and car washing, instead of treated using drinking (potable) water which is expensive.

    How does rainwater harvesting work?

    1. Rain is gathered from the roofs and passes through a filter outside the underground storage tank.
    2. The dirt particles and debris are seperated from the water. The cleaned watre flows to the tank. The dirt is washed to sewer to soak away.
    3. The top layer regularly overflows ensuring that any floatable material does not sour the water.
    5. During dry spells, if water in the tank drops below minimum levels the system will top up automatically with mains water. The volume of the tank ensures this rarely occurs.

    Is rainwater harvesting suitable for work as well as at home?

    Yes our systems can be used in schools, hospitals, offices and other commercial premises.

    How much water can a system save?

    Depending on your normal usage, it can save 30 to 50% of the treated drinking water from the mains in houses and up to and up to 80% of the treated drinking water in a business or commercial building.

    How much would this save on water bills?

    Depending on your normal usage, it can save 30 to 50% for the domestic user and 80% for the commercial user of the treated drinking water from the mains. Having metered water is the best way of appreciating the difference.

    How much rainwater does a system collect?

    This depends on the area and angle of your roof, and your rainfall. Averages of 100,000 litres per household are commonly quoted, much more for large roofed commercial buildings.

    Is it only for new buildings?

    No, it can be installed in existing buildings, but will cost more, because of the extra plumbing required.

    Is it only for houses?

    No, bungalows and commercial premises are also very suitable, the only limitation is the area of the roof to capture rain, compared to the number of users; this puts a limitation on flats and apartments.

    How much does it cost?

    Domestic systems can cost from about ?2500 up to ?4000 plus including installation costs, depending on size of tank. Commercial systems can cost a lot more depending on size and requirement, but usually have a much quicker ‘pay back’ period due to the size of roof and high usage.

    So, why should people buy Rainwater Harvesting systems?

    To save on water bills and show they use a precious resource responsibly to make a difference to our environment.

    How clean is the water?

    The rainwater is filtered as it enters the storage tank, to remove particles and other matter. It is kept in the dark and kept oxygenated to discourage algal growth, and properly designed systems are designed with calming inlets, which ensure that any sediment at the bottom of the tank does not get stirred up. The water is not drinking water fit for humans.

    Could rainwater get into my drinking supply?

    Not in a properly designed system, the pipework is entirely separate and should be identified as non-potable.

    What happens when there is no rain?

    When there is a prolonged spell without rain, the water level in the storage tank will fall to a minimum level. At this level, a float switch will open a valve from the normal mains supply and keep the storage tank topped up, until it is filled by rain again. Normal system design should allow up to a week without rain, given normal usage.

    Could rainwater get into my drinking supply?

    Not in a properly designed system, the pipework is entirely separate and should be identified as non-potable.

    Sewage Treatment FAQs

    Why do we need to treat sewage?

    Treatment of sewage is essential to ensure that the receiving water into which the effluent is ultimately discharged is not significantly polluted. However, the degree of treatment required will vary according to the type of receiving water. Thus, a very high degree of treatment will be required if the effluent discharges to a fishery or upstream of an abstraction point for water supply. A lower level of treatment may be acceptable for discharges to coastal waters where there is rapid dilution and dispersion.

    What does Sewage treatment involve?

    It involves:
    1. The removal of solids by physical screening or sedimentation.
    2. The removal of soluble and fine suspended organic pollutants by biological oxidation and adsorption processes.
    Both forms of treatment produce sludge as by-products and these have to be treated and used or disposed of in an economical and environmentally acceptable way.

    Why do we need to treat sludge?

    All methods of sewage treatment generate organic sludges as by-products and these must be managed separately from the liquid sewage. Raw (untreated) sludges have a very high oxygen demand and must not be allowed to enter the water environment.

    There is, therefore, a need to deal with them in a way that permits their ultimate disposal in an environmentally acceptable and sustainable manner. The sludge ‘route’ selected for a given sewage treatment works will depend on several factors including its location, the availability of suitable farm land, the characteristics of the sludge and the overall cost.

    Is the system gravity fed?


    Does the purchase price include delivery, commissioning & supervision of installation?


    Installation FAQs

    What is a percolation test and who carries it out?

    A percolation test is a method of assessing how much water can drain away through your plot’s subsoil (a subsoil porosity test). It is performed by excavating a small area and monitoring the time taken for the water to drop in minutes per inch. Our own Engineer will come out and perform this test onsite for you.

    Where can I discharge to?

    Every location has its own characteristics and hence there can be either many discharge options, or none at all. Popular options include soakaways, drainage ditches or discharging to streams, rivers & watercourses. Again, it is important to remember that what is judged acceptable to the authorities in one location can be turned down by another, so the first step is always to consult your local Regulatory Body.

    Can I connect surface water into the plant?

    No – Surface water cannot enter a treatment plant and must be drained away separately

    Can I use the discharged water?

    Ireland Waste Water does not recommend the discharged water be used for any purpose. The water exiting a treatment plant remains wastewater and should be disposed of as such.

    Maintenance FAQs

    Do treatment plants need maintenance?

    Treatment plants require very little maintenance. The main task required is the periodic pumping-out of the waste solids that simply cannot be broken down by the biological process.

    How often do I need to empty my unit and why?

    Emptying is known as ‘Desludging’. Desludging intervals depend on the size of the unit and several factors, but with our Euro Bio it only requires desludging once every 6 years.

    Can I get someone to take care of all this for me?

    Yes. Ireland Waste Water offers various Service & Maintenance contracts throughout Ireland so you need never need worry about the running of your treatment plant.

    What would happen in the event of a power cut?

    A power cut should not cause any particular problem, but in all events, check that unit has restarted after a power cut of any length of time and reset the control panel if necessary. If the unit fails to restart then Contact Our Office.