Research into the impact of human faecal waste (faeces, urine and toilet paper) disposal on non-serviced wilderness areas appeared in the 1970s and in the 1980s. While recent studies have noted issues caused by unappropriate human faecal waste disposal in back-country areas, they have concentrated on other recreation impacts such as physical disturbances caused by camping and trampling, both in the US and Australia. This gap in the knowledge of recreation impacts is recognized and is especially important in a context of increased visitor use of the back-country.
A Minimal Impact Bushwalking (MIS) Strategy was adopted by the Tasmanian Parks and Wildlife Service in an Attempt to encourage bushwalkers to dispose of their waste in an environmentally safe manner. These guidelines advise campers to choose a toilet site that is at least 100m away from any water source, where they should bury human waste (faeces and toilet paper) in a cat-hole approximately 15cm deep. They are also advised to carry out used tampons. These guidelines were based on the Leave No Trace campaign in the USA. However, there are very few scientific data supporting the Australian guidelines. Recent surveys of campsites revealed the degree of non-compliance with MIB guidelines, with many cases of unburied toilet paper and/or faeces being recorded.
The persistence of toilet paper around campsites is primarily an aesthetic issue, the importance of which escalates if Tasmania’s reputation as the ‘clean, green State’ is to be upheld, especially in the Tasmanian Wilderness World Heritage Area. There has been no published study that directly addresses the relative breakdown rates of toilet paper, tissues and tampons buried in the ground in natural environments. Limited information from North American research states that toilet paper is slow to breakdown, and may be dug up by animals. The practice of burning toilet paper is neither desirable in environments dominated by soils high in organic matter, nor is it a management option for the fire-free ‘fuel-stove only’ regions of western Tasmania. It has been suggested that recreationalists should carry our used toilet paper. While this suggestion has been publicized on some Tasmanian walk maps, it is not a general recommendation of the current Tasmanian MIB guidelines.
The research reported in this paper was undertaken to determine: whether the environments frequented by bushwalkers in Tasmania differed in their ability to break down toilet paper, tissues and tampons; the periods required for breakdown; the impact of nutrient additions on the breakdown of paper products; and, the influence of depth of burial, climatic and edaphic attributes on breakdown rates. The management implications of the results are discussed.
Methodology…
Discussion and Conclusion:
Unbleached toilet paper does break down faster than bleached toilet paper and tissues. However tampons stand our as being most resistant to decay, with the other products not strongly differentiated in their rates.
The sites that recorded the greatest decay rates were those that were warm, relatively dry and not acidic. Breakdown of most products was well advanced within 6 months of burial at these sites. Microbial activity, measured by cellulose assay, was also greater at these sites. Line found that the cellulose flocking used n disposable nappies decayed after 5 months in warm environments with neutral, fertile soils.
… Higher decay rates during the late summer-autumn period than during the spring-early summer period has also been reported elsewhere. However, our data show that three sites (coastal eucalypt, subalpine rainforest, montane moorland) recorded greater decay in the cooler months than in the warmer months for the fertilized bags.
Depth of burial is an important factor in decay at sites where soils freeze. Under such conditions, there is a difference in decay with depth down the soil profile during the early summer, though this difference is not evident later in the season. Our data show depth of burial to be largely unimportant across all sites in Tasmania, but in wetter areas where water tables are within 15cm of the surface, paper products are likely to decay more readily at 5cm depth than in 15cm depth. While decay may be slightly enhanced at shallower burial depths, access of faeces to native animals and transport of faecal bacteria may occur more readily at 5 cm depth than at 15cm depth. The burial of waste under rocks at the soil surface does not increase decay, and is inadvisable from a public health point of view.
… Environmental acceptability relates to variation from the natural condition of the soil, which would obviously be considerable where deposits remain intact over several years. In alpine and high altitude moorland environments decay is extremely slow. In our judgement it is both socially and environmentally undesirable to continue to advise people to bury their wastes in these environments. This would not be a major imposition on walkers, as locations in these environments are usually in close proximity to forest or scrub vegetation, which provide more privacy than buttongrass moorland and alpine vegetation.
If anything is to be carried out, tampons are an appropriate target. .. Walkers may place their waste under rocks in alpine areas because they are reluctant to damage alpine vegetation by digging. We hope that the results of this research and those from our vegetation study will convince them that it is less environmentally harmful to bury their waste than to leave it exposed.
Soil depth proved sufficient in parts of all our sites to enable burial of waste at 15cm, as is suggested by the code. However, obstructions such as roots, rocks or very hard clay soil made it difficult to dig a hole 15cm deep at some sites. Digging to that depth was impossible to severely challenging at most sites using plastic trowels of the kind sold in many outdoor stores. …so the 15 cm recommendation in the code should stand.
The above results suggest that the minimum impact bushwalking code should be amended to:1) to recommend no disposal of faeces, toilet paper or tissues in treeless vegetation above 800m in western Tasmania; 2) to emphasise that placement of waste under rocks causes more environmental harm than disposal by burial, even in alpine environments. 3) to emphasise that strong metal trowels are necessary to excavate holes for defecation in most wild places. The significantly longer decomposition times for tampons campared to toilet paper supports the current policy of carrying out tampons.
Walkers should also choose their toilet site carefully. Choose a well-drained soil in woody vegetation rather than a poorly drained soil or peat in alpine or moorland vegetation.