Human health and environmental impact of using sewage sludge on

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					Human health and environmental impact of
using sewage sludge on forestry and for
restoration of derelict land
Project Code: UKLQ09                                      .

Background                                                The    following   tasks    have      been
                                                          undertaken as part of the project brief:
Although there is a great deal of research and
                                                          Task 1: Literature review and risk
scientific data on sewage sludge application to land,
                                                          assessment of the human health
much of this relates to modest application rates on
                                                          impacts    of    sewage     sludge
agricultural land. In recent years there has been a
                                                          spreading on land:
substantial increase in the amount applied to
forestry, and to former opencast coal sites in the UK         a) The literature review has focussed on
for purposes of land restoration. Application rates of           health effects of spreading of sewage
sewage sludge have been considerably higher than                 sludge on non-agricultural land e.g.
traditionally practised, and sludge has been applied             for land treatment and remediation
using different techniques. There is concern that                such as derelict land and forestry.
poorly managed practices could result in risks to                The study has considered both the
human health; water, air and soil quality and                    microbiological components and the
biodiversity. Public and political interest is high and          chemical components of sludge e.g.
this project has addressed the need to review this               metals     and    persistent     organic
activity, and to develop decision support systems                pollutants. Issues such as odour
and guidelines to ensure that the activities will not            which affects quality of life and health
affect public health or adversely affect the                     in its wider sense have also been
environment.                                                     considered.

                                                              b) Consideration has been made to how
Aims                                                             the evidence of health effects is
                                                                 relevant to sites currently or
The project aims have been to:                                   potentially used for sewage sludge
                                                                 spreading on non-agricultural land,
   •   Carry out a detailed desk-based literature                and the potential pathways to man,
       review of human health impacts, and                       e.g. direct exposure and indirect
       environmental and ecological effects;                     through inhalation and ingestion. The
   •   Follow this up with quantitative assessment               source–pathway–receptor model has
       of sites where sewage sludge has already                  also been an important consideration.
       been applied; and
   •   Use this information to develop a systematic
       site suitability and risk assessment
c)   How the source, possible treatment                         Outputs
     processes and disposal methods for
     sewage sludge, in addition to weather and                  The systematic site suitability and risk
     environmental conditions at the time of                    assessment procedure will enable
     and after spreading, impact on the                         regulators to readily determine if a site is
     potential health effects has been                          suitable for sludge spreading and what
     addressed. How these factors impact on                     management and application rates are
     concentration and mobility of chemicals                    appropriate. Further work is now ongoing
     and pathogens has also been considered.                    within SEPA regarding how the outputs
                                                                from this research will be taken forward.
Task 2: Literature review of the environmental
and ecological effects of spreading of sewage                   Contacts for Further Information
sludge on non-agricultural land.
                                                                For more information on the research
Task 3: A detailed environmental assessment                     project, please contact:
has been undertaken for four sites where
sewage sludge has been used on forestry and                     SNIFFER
on restored derelict land. The focus of this task               Tel: 0131 557 2140
has been informed by the outcomes of tasks 1                    Email:
and    2    but    includes     analysing     and
characterising the native and restored soils /                  For further information on next steps
subsoils present at the sites (including the clay               following completion of the research in
and organic matter content), as well as surface                 Scotland, please contact:
and groundwater analysis.
                                                                Debbie Storm / Gayle Howard
Tasks 4 to 6: A decision support system has                     Public Relations
been developed to predict if sludge will result                 Scottish Environment Protection Agency
in an overall ecological improvement, or be of                  Tel: 01786 457700
benefit to non-food crops; and to predict the
effect of the sludge application on soil and                    The research outputs are available as five
surface and groundwater water quality.                          separate reports. Copies are available for
                                                                free download from:
A systematic site suitability and risk                 (search on ‘Project
assessment procedure has been developed to                      Code’ UKLQ09)
enable regulators to predict site suitability,
management and application rates and to                         Partners
predict public health, environmental, and
                                                                • Scottish Environment Protection
ecological effects.
                                                                • Northern Ireland Environment Agency
                                                                • Scottish Government
                                                                • Forestry Commission
                                                                • Health Protection Scotland

                                                                Phone: 0131 5572140

                                                                Date produced:
                                                                September 2008

              SNIFFER, First Floor, Greenside House, 25 Greenside Place, Edinburgh, EH1 3AA
Tel: +44(0) 131 557 2140 Fax: +44(0) 131 652 3670 Email:
                                        Scottish Charity No SC02375,
    Company No SC149513. Registered in Edinburgh. Registered Office: Edinburgh Quay, 133 Fountainbridge,
                                            Edinburgh, EH3 9AG