Surface disposal

Applicable to the following sanitary systems Single pit system Waterless system with alternating pits Pour flush system with twin pits Waterless system with urine diversion Blackwater treatment system with infiltration Blackwater treatment system with sewerage (Semi-) Centralized treatment system Sewerage system with urine diversion

Inputs Faeces, Dry cleansing materials, Faecal sludge, Treated sludge

Application Level Management Level Household: x Household: x Neighbourhood: x Shared: xx City: xx Public: xx xx - suitable, x - less suitable, o - not suitable

Description

Surface Disposal refers to the stockpiling of sludge, faeces, biosolids, or other materials that cannot be used elsewhere. Once thematerial has been taken to a Surface Disposal site, it is not used later. This technology is primarily used for biosolids, although it is applicable for any type of dry, unusable material.

One application of Surface Disposal that is shown on the System Templates is the disposal of dry cleansing materials, such as toilet paper, corn cobs, stones, newspaper and/or leaves. These materials can not always be included along with other water-based products in
some technologies and must be  separated. A rubbish bin should be provided beside the User Interface to collect the cleansing materials. Dry materials can be burned (e.g. corn cobs) or disposed of along with the household waste.

When there is no demand or acceptance for the beneficial use of biosolids, they can be placed in monofills (biosolids-only landfills) or heaped into permanent piles. The main difference between Surface Disposal and Land Application is the application rate. There is no limit to the quantity of biosolids that can be applied to the surface since there are no concerns about nutrient loads or agronomic rates. There is however, concern related to groundwater contamination and leaching. More advanced surface disposal systems may incorporate a liner and leachate collection system in order to prevent nutrients and contaminants from infiltrating the groundwater.

Landfilling biosolids along with Municipal Solid Waste (MSW) is not advisable since it reduces the life of a landfill which has been designed for the containment of more noxious materials. As opposed to more centralized MSW landfills, Surface Disposal sites can be situated close to where the faecal sludge is treated, limiting the need for long transport distances.

Adequacy

Since there are no benefits gained from this type of disposal technology, it should not be considered as a primary option. However, where acceptance towards biosolid use does not exist, the contained and controlled stockpiling of biosolids is far preferable to
uncontrolled dumping.

Biosolids can be applied in almost every climate and environment, although they should not be stored wherethere is frequent flooding or where the groundwater table is high.

Health Aspects/Acceptance

Since the Surface Disposal site is located far from and protected from the public, there should be no risk of contact or nuisance.
Care should be taken to protect the disposal site from vermin and from pooling water, both of which could exacerbate smell and vector problems.

Maintenance

Maintenance staff should ensure that only appropriate materials are disposed of at the site, and must maintain control over the traffic and hours of operation. ^[1]

Pros & Cons

How to build

Costs

References

1. ↑ Tilley, Elizabeth et al, 2008. Compendium of Sanitation Systems and Technologies. Swiss Federal Institute of Aquatic Science and Technology (Eawag). Dübendorf, Switzerland., pp.149-150 ISBN 978-3-906484-44-0