A bucket toilet is a basic form of a dry toilet whereby a bucket (pail) is used to collect excreta. Usually, feces and urine are collected together in the same bucket, leading to odor issues. The bucket may be situated inside a dwelling, or in a nearby small structure (an outhouse). Where people do not have access to improved sanitation – particularly in low-income urban areas of developing countries – an unimproved bucket toilet might be better than open defecation. They can play a temporary role in emergency sanitation, e.g. after earthquakes. However, the unimproved bucket toilet may carry significant health risks compared to an improved sanitation system. The bucket toilet system, with collection organised by the municipality, used to be widespread in wealthy countries; in Australia it persisted into the second half of the 20th century. Once the basic bucket toilet has been "improved", it evolves into a number of different systems, which are more correctly referred to as either container-based sanitation systems, composting toilets, or urine-diverting dry toilets. Applications Unimproved toilets Bucket toilets are used in households and even in health care facilities in some low- and middle- income countries where people do not have access to improved sanitation. In those settings, bucket toilets are more likely to be used without a liner, or the liner is not removed each time the bucket is emptied. This is because the users cannot afford to regularly discard suitably sized, sturdy liners. Instead, the users may place some dry material in the base of the bucket (newspaper, sawdust, leaves, straw, or similar) in order to facilitate easier emptying. Cold climates Bucket toilets have been historically common in cold climates where installing running water can be difficult and expensive and subject to freezing-related pipe breakage, for example in Alaska and rural areas of Canada and Russia. Emergencies In natural disasters and other emergencies, the portability of bucket latrines can make them a useful part of an appropriate emergency response, especially where pit latrines cannot be isolated from floodwater or groundwater (potentially leading to groundwater pollution) and where the contents can be safely disposed into sanitary systems, taking measures to avoid contact with the contents. Different organizations give advice on how to build bucket toilets in case of emergency. The Twin Bucket Emergency Toilet system (a two bucket system), for example, has been developed in Christchurch, New Zealand following their infrastructure destroying earthquake