Tutkimuksen tavoitteena oli tuottaa kansainvälisesti vertailtavaa tietoa suomalaisten viljelymaiden hivenalkuaineista. Aineistona käytettiin maanäytteitä, jotka oli kerätty kansallisen seurantaohjelman viimeisimmässä näytteiden keruussa vuonna 1998. Kyseisestä aineistosta valittiin 338 maanäytettä, jotka edustivat tasaisesti koko Suomen viljeltyä aluetta. Kukin näyte oli otettu neljänä osanäytteenä pellon muokkauskerroksesta. Näytteistä analysoitiin arseeni (As), kadmium (Cd), kromi (Cr), kupari (Cu), lyijy (Pb), elohopea (Hg), nikkeli (Ni), seleeni (Se), vanadiini (V) ja sinkki (Zn). Analyysi tehtiin kansainvälisen standardimenetelmän ISO 11466:n mukaisesti käyttäen kuningasvesiuuttoa (aqua regia). Tuloksista laskettiin tärkeimmät tilastolliset parametrit maalajiryhmittäin ja kasvinviljelyvyöhykkeittäin. Hivenalkuaineiden jakautumisesta pitoisuusluokkiin muotoiltiin graafiset esitykset ja pitoisuuksien maantieteellisestä jakaumasta teemakartat. Tutkimus oli osa vuosina 2004 2007 toteutettua, Maa- ja metsätalousministeriön rahoittamaa yhteistutkimushanketta Raskasmetallikuormitusten arviointi ja vähentäminen Suomen maatalousekosysteemeissä . Hankkeen tavoitteena oli ensinnäkin selvittää viljelymaiden raskasmetallipitoisuuksia valtakunnallisesti käyttäen kuningasvesiuuttoa. Toiseksi tutkittiin kasvinviljely- ja maidontuotantotilojen viljelymaan raskasmetallipitoisuuksia kuningasvesiuutteesta ja hapan (pH 4,65) ammoniumasetaatti-EDTA -uutteesta siten, että näytteet otettiin muokkauskerroksesta ja jankosta. Kolmanneksi hankkeessa analysoitiin raskasmetallien tilakohtaisia peltotaseita kasvinviljely- ja maidontuotantotiloilla. | This study was part of a three-year (2004-2007) project entitled Assessment and reduction of heavy metal inputs into Finnish agro-ecosystems that was funded by the Ministry of Agriculture and Forestry in Finland. The aims of the project were to clarify: 1) aqua regia extractable trace elements in Finnish cultivated soils with the international standard method at a national level; 2) aqua regia and AAAc-EDTA extractable trace elements in the top- and subsoil of Finnish arable land at selected crop and dairy farms; and 3) field mass balances of trace elements on the selected crop and dairy farms at the farm level. The main aim of this study was to produce internationally comparable knowledge on the status of cultivated soils in Finland. From the soil material collected during the latest sampling process under the national monitoring programme in 1998, 338 samples were selected for this investigation. The sampling sites were situated evenly over the whole cultivated area in Finland. Samples taken as four sub-samples from the plough layer were analysed for arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), vanadium (V) and zinc (Zn) using aqua regia extraction according to an international standard method (ISO 11466). General statistical indicators of the analytical results of trace element concentrations are presented by soil type groups and by plant cultivation zones. Distributions of the results into the concentration classes are shown graphically and geographical distributions of the trace element concentrations are presented on the thematic maps. | v | ok | Myynti MTT, Tietopalvelut 31600 Jokioinen. Yksikön huom.: MAA, MPL | MPL | Viljelymaiden seurantaohjelma Suomessa Hivenalkuaineiden kokonaispitoisuudet peltomaissa : vuonna 1998

The characteristics of groundwater systems and groundwater contamination in Finland, Norway and Iceland are presented, as they relate to outbreaks of disease. Disparities among the Nordic countries in the approach to providing safe drinking water from groundwater are discussed, and recommendations are given for the future. Groundwater recharge is typically high in autumn or winter months or after snowmelt in the coldest regions. Most inland aquifers are unconfined and therefore vulnerable to pollution, but they are often without much anthropogenic influence and the water quality is good. In coastal zones, previously emplaced marine sediments may confine and protect aquifers to some extent. However, the water quality in these aquifers is highly variable, as the coastal regions are also most influenced by agriculture, sea-water intrusion and urban settlements resulting in challenging conditions for water abstraction and supply. Groundwater is typically extracted from Quaternary deposits for small and medium municipalities, from bedrock for single households, and from surface water for the largest cities, except for Iceland, which relies almost entirely on groundwater for public supply. Managed aquifer recharge, with or without prior water treatment, is widely used in Finland to extend present groundwater resources. Especially at small utilities, groundwater is often supplied without treatment. Despite generally good water quality, microbial contamination has occurred, principally by norovirus and Campylobacter, with larger outbreaks resulting from sewage contamination, cross-connections into drinking water supplies, heavy rainfall events, and ingress of polluted surface water to groundwater.

Stable isotopes (δ¹⁸O, δD), dissolved silica (DSi) concentration and major ion composition were used to indicate groundwater/surface-water interaction between the aquifers, the rivers and a lake in the high-latitude Lake Pyhäjärvi catchment in Finland. Significant differences were recorded in water chemistry between the groundwater and surface waters, especially in the stable isotope composition and DSi concentrations, which could thus be used as tracers. The baseline data on isotopic patterns and hydrogeochemistry in the hydrological cycle were provided by a 1-year monitoring survey in this snow-type catchment area. The proportions of groundwater in the rivers, the lake inshore area and in a groundwater abstraction plant were calculated using stable isotopes and DSi. Two inflowing rivers had distinct differences in their water chemistry. DSi has potential as a tracer in the river environment, whereas stable isotopes were more applicable in the lake environment. Locally, near the shoreline, the effect of discharging groundwater on the lake-water quality could clearly be observed. Furthermore, infiltration of the lake water into the aquifer could be observed near the pumping wells onshore. This infiltration presents a potential risk for the water quality of water supply (intake) wells. Frequent sampling is needed as part of the evaluation of the level of groundwater/surface-water interaction in snow-type catchments in order to estimate the magnitude of seasonal variation. In groundwater/surface-water interaction studies, spring thaw and high-precipitation events could be problematic, in terms of both sampling and interpreting results.

Managed aquifer recharge (MAR) refers to intentional infiltration of surface water to an aquifer for facilitating natural water treatment and storage. MAR is often used as a treatment to remove natural organic matter from water in drinking water production. The sustainability of MAR depends on how the aquifer capacity to remove organic matter will evolve over the long term. This report explores the behavior of MAR systems by using a natural lake–aquifer system as a surrogate. Natural infiltration of lake water to groundwater has been going on for millennia at the research site in Finland chosen for this study. According to the measurements, the mean concentration of total organic carbon (TOC) in lake water was 3.0 mg/L. Within the distance of 3 m from the lake bank (retention time 7–15 days), already 46% of TOC was removed. At greater distances along the flow paths within the aquifer, 80–90% of TOC was removed. The observed TOC removal in the aquifer was slightly higher than the reported values at MAR sites, indicating that MAR can be an effective solution to the problem of removing natural organic matter in the long term. Signs of accumulation of organic matter were not observed in the aquifer, which suggests that biodegradation was the main removal method, and the role of sorption was minor. Several processes had an impact on oxygen levels in the aquifer, which led to spatial and seasonal changes in the redox conditions and in the iron and manganese concentrations in groundwater.

Three-dimensional geological and groundwater flow models of a submarine groundwater discharge (SGD) site at Hanko (Finland), in the northern Baltic Sea, have been developed to provide a geological framework and a tool for the estimation of SGD rates into the coastal sea. The dataset used consists of gravimetric, ground-penetrating radar and shallow seismic surveys, drill logs, groundwater level monitoring data, field observations, and a LiDAR digital elevation model. The geological model is constrained by the local geometry of late Pleistocene and Holocene deposits, including till, glacial coarse-grained and fine-grained sediments, post-glacial mud, and coarse-grained littoral and aeolian deposits. The coarse-grained aquifer sediments form a shallow shore platform that extends approximately 100–250 m offshore, where the unit slopes steeply seawards and becomes covered by glacial and post-glacial muds. Groundwater flow preferentially takes place in channel-fill outwash coarse-grained sediments and sand and gravel interbeds that provide conduits of higher hydraulic conductivity, and have led to the formation of pockmarks on the seafloor in areas of thin or absent mud cover. The groundwater flow model estimated the average SGD rate per square meter of the seafloor at 0.22 cm day⁻¹ in autumn 2017. The average SGD rate increased to 0.28 cm day⁻¹ as a response to an approximately 30% increase in recharge in spring 2020. Sensitivity analysis shows that recharge has a larger influence on SGD rate compared with aquifer hydraulic conductivity and the seafloor conductance. An increase in recharge in this region will cause more SGD into the Baltic Sea.