Measurements and Activities for Mud Removal and Disposal of Sediments " Novi Sad, 27. mart „Environmentally friendly water management in plain areas„ eWAM HUSRB/1203/121/237 Dejan Krčmar, PhD PMF – Department of Chemistry, Biochemistry and Environmental Protection

Why sediment?  The dynamic component of all aquatic systems may be a reservoir of accumulated toxic and persistent compounds of natural and predominantly anthropogenic origin due to the strongly expressed tendency of binding  In the sediment, there is a million times bigger concentration of pollutants (e.g. metal) than in the same volume of water  The source of secondary pollution “Time bomb” Resuspension –Flooding –Raising the floodgates - Mud removal –Bioturbation

Sediment Sustainable Management When and where to monitor sediment quality? How often? How to evaluate sediment quality? How does sediment affect water quality? – Which methods should be used? – Which pollutants should be monitored? – Which quality criteria should be used? Is that sufficient for making conclusions? What should be done when the sediment quality does not satisfy? – To remove the mud or leave it? What to do with the removed material? – Should it be disposed of? Or can it be spread onto the coast, adjacent land or move to another aquatic environment? – Can it be used for material extraction? – What effect will sediment removal have on the aquatic system?

When and where? 1.Rating chemical status and trend of sediment quality - WFD (2000/60/EC) Each Member State should make the identification of contaminated sediment requiring remediation. If the quality of the sediment is bad and affects the achievement of good ecological status, Member State must, in accordance with Article 4 and Article 11, initiate appropriate action since contaminated sediments may pose a barrier to achieving good ecological status of water bodies. 2.In case of regular watercourse maintenance Maintenance of waterways Reducing the risk of flooding Coastal management... WFD only implies monitoring the quality of sediments and provides a framework within which the problem of sediment must and can be handled at locations where the ecological status is disrupted due to the degraded quality of the sediment. How?

 System dynamics – Spatial (horizontal and vertical distribution of pollutants) - design of monitoring – Weather (seasonal changes, the impact of sediment geochemistry and the process of "aging" on the bioavailability of pollutants) – Environmental conditions  Discrepancies between the chemical and ecological status – The impacts caused by the presence of pollutants whose presence in the sediments is not monitored, – The synergistic or antagonistic effect of the pollutants, – The occurrence of pollutants in different chemical forms (e.g. metals), which significantly affects their toxicity, – Different sensitivity of different organisms to different types of pollutants. The complexity of the process of quality assessment of sediment

Additional:  Complex and incomplete regulation,  The lack of data on the concentrations of the compounds and elements in sediments,  Lack of data on reference conditions,  There is no homogeneous classification of sediment,  There are no agreed criteria on sediment quality,  Conventional methods aim to determine the concentrations of pollutants in the sediment, therefore they are not suitable since they overestimate the bioavailable fraction. Available fraction Total PAH concentration Accumulated fraction Receptor

Sediment (mud removed material) as waste If the definition of waste in Directive on Waste (2006/12/EC codifies Directive 75/442/EEC and repealing in its subsequent amendments) is applied, it indicates that the sediment after mud removal automatically becomes a waste, regardless of the contamination level. The definition of waste is “any substance or object in the categories set out in Annex I which the holder discards or intends or is required to discard”. In Annex I of this Directive the following categories are stated: Q15 “Contaminated materials, substances or products resulting from remedial action with respect to land”, Q16 “Any materials, substances or products which are not contained in the abovementioned categories” When does mud removed material become waste?

Classification of mud removed material depends on the assessment of hazardous nature of waste by : The European waste catalogue (2000/532/EC) Hazardous Waste Directive EU (91/689/EEC) When does mud removed material become hazardous waste? Clean and free of adverse ecotoxic effects Contaminated with the expression of ecotoxic effects Mud removed material harmless hazardous WASTE Sediment that is too contaminated to be transferred to another water environment, should not automatically be classified as hazardous waste!

 Limit values for pollutants for assessing the status and trends of sediment quality, i.e. the target value, the maximum concentration value and remediation value  and the values ​​of pollutants that are used in mud removal and dislocation of the sediment from the water stream, i.e. the target value and remediation, the limits value and verification level Sediment quality standards in Serbia Regulation on limit values ​​for pollutants in surface and ground waters and sediments and deadlines for their achievement (Official Gazette of RS, 50/2012)

Status assessment 1.Rating chemical status and trend of sediment quality  Includes arsenic, heavy metals, PAHs, PCBs, organochlorine pesticides, mineral oils

Mud removal for maintenance 2.In the case of regular maintenance of waterways  Includes arsenic, heavy metals, PAHs, PCBs, organochlorine pesticides, mineral oils

What to do with mud removed material? Class Criterion Ways of dealing with mud removed sediment 0  Target value Concentrations of contaminants in the sediment are at the level of natural background. Sediments can be displaced without any special protection measures. 1 > Target value  Limit value Sediment is slightly polluted. During dislocation the disposal without special measures of protection is permitted in the band width of up to 20 m in the vicinity of watercourses. 2 > Limit value  Verification limit 3 > Verification level  Remediation value The sediment is contaminated. Its disposal is not allowed without special measures. It is necessary to keep in the controlled conditions along with the special protection measures to prevent the spread of pollutants in the surroundings. 4 > Remediation value Extremely polluted sediments. Remediation is obligatory or keeping mud removed materials in controlled conditions with special protection measures to prevent the spread of pollutants into the environment.

Correction of metal content for the given sediment Correction of organic substances for the given sediment. Correction of threshold values

However, the quality of the sediment is not the list of chemical substances concentration...  The total concentrations of contaminants - despite correction, the estimated risk often exceeds the actual risk.  Necessary research in order to fully understand the processes that define the bioavailability and the development of quantitative descriptive models for these processes.  It is necessary to develop chemical and biological tests for quick and easy assessment of the bioavailability and thus the quality and sediment assessment of risks to the environment.  Data on the natural level of pollutants (especially metals)  Eco-toxicity, benthic community structure, bioaccumulation

Safe mud removal and disposal of sediments Selecting the right alternative for mud removal/ remediation is based on balancing the many demands in terms of: technical feasibility, economic feasibility and environmental protection including the DISABLING THE EXPANSION OF HARMFUL SUBSTANCES INTO THE ENVIRONMENT. The basic roads of pollutant losses during mud removal, treatment and disposal of sediments : 1.Resuspension of sediment 2.Dissolution / desorption of the pollutants 3.Leaching

PHASE I - Initial characterisation and potential for desorption PHASE II - works control on mud removal PHASE III - control of the deposited material and leachate from the landfill and protection measures Yes No Yes No Yes No Surveillance monitoring of the landfill and groundwater Continued work with occasional control of pore (leachate) water The temporary interruption of work and review of some of the stabilisation options of mud removed material. After that, work continuance with planned protection measures. Is there a leakage from the landfill? Mud removal and deposition with special protection measures Is there a risk of desorption of pollutants Sediment quality satisfies the criteria? INITIAL POLLUTION CHARACTERISATION WORK PLANNING Mud removal and deposition without any special protection measures PHASE IV - surveillance monitoring

Thank you!