Proposal of partnership to create an Active Group to ...

Ecologia Applicata srl. Servizi per l'Ecologia Organizzazione Scientifica di Ricerche Ambientali Convenzionata con l'Università degli Studi di Milano

Proposal of partnership to create an Active Group to apply the Hypolimnic Water Withdrawal and Oxygenation ( HYWAWO ) in some eutrophycated shallow or normal Lakes

Milano: Via Porpora, 9 Tel. 02 / 2895978 Telefax : 02/2871159 e-mail : [email protected] sito web : www.ecologia-applicata.it Numero Anagrafe Nazionale delle Ricerche 602910X9 Part.IVA 09453070154 - N.Reg.Soc.2876/7334/26/MI - N. Reg. Ditte 1294361

Intro The term “ eutrophication” define an increase of productivity in aquatic ecosystem due to the increasing level of nutrients, in particular nitrogen phosphor. This higher level is what causes unpleasantly things like a decrease in transparency of water and in quantity of oxygen dissolved that definitely modify all characteristics of aquatic ecosystems and that can result in degeneration of water (pollution). In lakes eutrophication is a natural process that require a long time because of filling in of the lake basin. All human activities can speed up the natural process through excessive emissions of nutrients (wastewater, illegal dumps and unauthorized occasional dumps) The nutrients that that can set limits on the phytoplantonic development can be defined in a general way as nitrogen and phosphor. The phosphor and, less, nitrogen are the only factors that we can control because of other substrates that can influenced the growth of algae comes from sources on which is non possible have some kind of supervision (carbon from atmosphere and microelements that comes lake ). So, a decrease in loads of nutrients from a spread and by point’s origin is the first thing to do to beginning the recovery of a lake. The experience is a demonstration that is not enough take action on external loads to hit the target (recovery). Causes can be list as follow: - a decrease of the load is not enough to make a significant reduction of the eutrophic level but only to cause better general conditions of the lake. - The presence of inland loads of phosphor because of the release of bottom sludge can make useless all benefits obtained with a decrease in exterior load, especially in not very deep lakes. In these cases a direct operation in the water body can have a key role making faster process of recovery of a lake The effects of these operations can be different from lake to lake and must very carefully consider based on the kind of lake Since now there are some techniques of direct operations: -

exportation of bio-masses (algae, macrophyite and fishes) bio-manipulation of food chains circulation/ hypolimnic aeration dilutions washout deactivation of the bottom sludge chemical precipitations of phosphor hypolimnic water withdrawal a decrease in water level of the lake

Our experiences, validate by several publications, put under a spotlight how the hypolimnic water withdrawal together with a possible oxygenation of deep water in some critics moments of the year is the technique that achieved best results with a minimum perturbation of the lake ecosystem.


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In fact this technique is base on the fact that in the eutrophic lakes during the stratification period the concentration of oxygen tends to decrease because of mineralization process of materials that sediments and a decrease of possibility of exchange with superficial water rich in oxygen and poor of phosphor with deep waters rich in phosphor and poor in oxygen thanks to pipes that can reach the most deep locations. Also in shallow lakes it is possible to work knowing stratification period by special analytical probe. The presence of hydrogen sulphate in waters in contact with the bottom in particular periods of anoxic is due to a decrease of sulphate to sulphur in presence of a red ox potential very low o even negative. In these cases the hypolimnic withdrawal can has to have an oxygenation treatment online and be sending on bottom of the lake. Oxygenated waters that come back on the bottom surface are able, following time periods to measure from time to time, results fundamental to make stable the concentration of phosphor accumulated in sediment, not allowing the release. An active proposal The applications ( in Italy the law 152/99 and its updates on a better quality of superficial water bodies / lakes ) pushed some administrations toward direct operations in attempt to speed up the recovery of very eutrophycated lakes to a natural situation of pre-eutrophication. In Italy, among other systems, we had operation of hypolimnic withdrawal and oxidation for Serraia’s lake (TN) and Annone’s lake ( 10 m.. -328 ft - max deep ) (LC). All this operations have seen an executive projection from the same engineering society (Arvetech of Milan),and, in some of these cases, the direct and indirect scientific supervision of prof. Giuseppe Chiaudani, already teacher of Ecology in the University of Milan, water monitoring and co-ordination by Ecologia Applicata srl. Scientific Organization of Environmental Research in agreement with University of Milan and with one or more specialized University Department ( UNIMI – Biology Department of Biology. Prof. Bruno Rossaro). Data collected during this operations, the cooperation of teams and experience achieved are things that lead to the idea of establish an Active Group Specialized in Hypolimnic Withdrawal and Oxygenation (HYWAWO) able to make up a recovery operation for a eutrophycated lake. A possible partnership with a local University and Engineering Group. is retained very well considering the firm vocation for experimental activities. The experience achieved with the Public Administration allowed us to establish a way to work that can be resumed in five different steps: -

individuation of an hypothetical necessity analysis of the limnologist situation with data, monitoring and an elaboration of a project of lake or river recovery partnership with local University and Technical Government Agency or local citizen’s association elaboration and presentation of the project to the Authority activities

Step 1 and 2 are scientifically concern Step 3 and 5 are common concern Step 4 is an engineering concern The first step is not a heavy part of the budget; instead step two is the most expensive one, because of high direct costs. Other steps are consequences of the first two. Milano: Via Porpora, 9 Tel. 02 / 2895978 Telefax : 02/2871159 e-mail : [email protected] sito web : www.ecologia-applicata.it Numero Anagrafe Nazionale delle Ricerche 602910X9 Part.IVA 09453070154 - N.Reg.Soc.2876/7334/26/MI - N. Reg. Ditte 1294361

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Monitoring activity plans medium costs for around 90-120.000 euro/by year (two-three points of sampling, four-six of deep, ten samples by year) every lake. Considering that this activity should be going for at least two or three years cost is to be between 180-360.000 euro. If, following the first year of monitoring (indispensable to optimised the project of the operation), the elaborated project would become executive, costs for the second and third year could be included in the general project funded by Public Institution. Is correct underline the fact that oxygenation activity represents a secondary aspect in a direct operation on the lake. Even being fundamental under some conditions ( presence of sulphydric acid and rich in phosphor salts.) The main aspect of a partnership is the applicative engineering on dissolution of oxygen in water, analytical work ( analysis on line by special probes ) and in the communications aspect that, in our opinion, could be a very rich source to spend for other applications with Public Administration or on an international level. The preservation of good water sources represents the first priority underlined during some summits between executive administration of Govern that we have course in the world. Lakes are the largest good water reserve available and they tends to degradation very quickly mainly for antropic pressure. The speed increasing of recovery process with direct operations and particularly with the “Hypolimnic Water Withdrawal and Oxygenation technique ” is to be consider as the absolute priority that very slowly take in direction of many regional and national programs Administration, and we can include also real international emergencies (China, Est-Europe countries, Africa and Asia in general).

Milano 2010-03-01

Paolo Broglio Scientific Director


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