"This is because glass can easily fall out and break when the crate is picked up. Broken glass on the footpath, kerbside or road could hurt the collectors, pedestrians, cyclists and other community members – which we obviously don't want," she said.
Over-filling is the most common reason for crates not being emptied by collectors. "It's the biggest mistake people make, with putting in non-glass items, such as plastic bottles, a close second."
Council had received feedback from some residents to increase the size of the glass collection crate but Maiden said that this wouldn't suit everyone.
"We also get calls to say the crate is too big. We realise that one size does not suit all households. But it's the New Zealand standard size receptacle for residential glass collections and has worked well in other council areas.
"The 45 litre crate size maximises the amount of glass that can be collected whilst still being easy enough for the average person to lift when it's full of glass. It also suits the collectors, who lift around seven tonnes of glass each day" she said.
Ratepayers who frequently had too much glass for one crate can order a second one for $26 by visiting the council website or the Customer Service Centre at 91 Willow Street.
The council would be introducing a full kerbside service in 2021 to collect rubbish, mixed recycling and organic (garden and/or food) waste. The kerbside glass collection service was introduced as an interim service, filling a gap left in the market when private waste collectors ceased collecting glass for recycling in March 2018.