Debris, rubbish and invasive aquatic weed was entering the bay from two rivers (approx 500 hectres water space). Cardiff Harbour Authority launched a competitive tender for a range of equipment to undertake a wide range of environmental responsibilities.
Liverpool Water Witch provided a successful solution.
- Keep the bay clear of natural/man-made debris:
- Trees, branches, large floating mats of aquatic weeds (Canadian pond weed and Milfoil) submerged plants rooted in sediment, reed beds and the occasional animal carcases
- Algae scum on the water surface
- Household furniture, telegraph poles, gas bottles, trolleys, tyres - and even the odd motor vehicle!
Equipment provided by Liverpool Water Witch included:
- Mk. 3 Water Witch workboat
- 4 Skipper barge units - with a capacity of 24m3 providing effecient storage and transfer facilities for debris
- Open top and tank skips - for storage and and transfer of solid and liquid waste
- 200m solid bouyancy debris boom
- MOP Oil recovery skimmer
- Fire fighting/salvage pump - 41 litres per second capacity
- Weed cutter
- Weed ripper - for removing bottom-rooted plants
- Silt bucket
- Log grapple
- Crane attachment
As with all Water Witch Workboats, the craft was built to Lloyds Register of Shipping Classification standards.
- During an intial 12 months over 892 tonnes (3,408m3) of litter and debris was removed by one Mk. 3 Water Witch boat.
- An average of 10 skip loads of waste removed each week
- Salvage pump enabled emergency assistance to be given to a sinking vessel, and a small craft on fire
- In periods of heavy rains, the boat recovered approximately 8 skip loads (48m3) per day
- Specialist equipment attached to the boat made complicated pollutant removal possible. Algae scum that accumulated on the waters surface (especially undesirable near-by residential developments) was removed using the general purpose basket.
The cardiff harbour Authority had initially investigated buying seperate vessels to deal with the range of functions required:
- Debris collection boat
- Oil spill response unit
- Removal of aquatic weed equipment
- Algae filtration system
Water Witch met all these demands with one versatile workboat.