The spatial distribution and source of arsenic, copper, tin and zinc within the surface sediments of the Fal Estuary, Cornwall, UK

ABSTRACT Estuarine sediments commonly form major sinks for contaminants released during industrial activity. Many industrial processes lead to the release of metals initially in solution, which can then be adsorbed on to, for example, Fe hydroxides or clay minerals. However, in the mining industry, there are two major contaminant waste streams: (1) metals discharged in solution via mine drainage; and (2) particulate grains of the ore‐forming or related minerals released after ore processing. The release of particulate waste can have a major long‐term impact on environmental geochemistry. In this study, we have mapped the distribution of arsenic, copper, tin and zinc within the surficial sediments of the Fal Estuary, Cornwall, UK, an area that drains a historically important polymetallic mining district. There are clear spatial variations in the contaminants, with the highest levels (> 2800 p.p.m. As, > 5000 p.p.m. Cu, > 3000 p.p.m. Sn and > 6000 p.p.m. Zn) within Restronguet Creek on the western side of the estuary. Mineralogical studies show that small (< 20 µm) grains of detrital arsenopyrite, chalcopyrite, cassiterite and sphalerite are very abundant within the surface sediments. Most of the sulphide grains are fractured, but mineralogically unaltered, although some grains show alteration rims caused by oxidation of the sulphides. The geochemistry and mineralogy are indicative of sediment supply from the discharge of particulate waste into the estuary during historical mining activity. Subsequently, this particulate waste has been largely physically and biologically reworked within the surface sediments. Although considerable effort has been made to minimize contaminants released via mine drainage into the estuary, the potential flux of contaminants present within the intertidal and subtidal sediments has not been addressed. Benthic invertebrates living within the area have adapted to be metal tolerant, and it is likely that the dominant source of bioavailable metals is a result of alteration of the particulate mine waste present within the intertidal and subtidal sediments.     

Tracing the source of mercury contamination in the Dorena Lake watershed, Western Oregon

Although fish in Dorena Lake are contaminated with mercury, the source of pollution in the watershed was unconfirmed until the present study. To trace the mercury to its source, fine-grained sediment samples were collected from the major streams of the watershed. A few samples of mine waste/tailings were also obtained from the Bohemia Mining District where mercury was historically used in processing gold and silver ore. Mercury concentrations in sediment from streams that do not drain the central mining district average 0.066 ppm, whereas samples taken downstream of the district contain 0.140-1.339 ppm. Mine waste/tailings contain 13.441 to >50 ppm mercury. The source of mercury contamination in the Dorena Lake watershed is thus the Bohemia Mining District. Historical and geological evidence strongly suggests that the mercury problem in the district resulted from gold-mercury amalgamation practices, but naturally high mercury content in mineralized areas cannot be ruled out with the data presented here.     

Hydrogeochemical characteristics of mine water in the Harz Mountains,Germany

Water samples (springs, creeks, mine adits) from different former mining districts of the Harz Mountains and the nearby Kupferschiefer (copper shale) basin of Sangerhausen were analysed for major ions and trace metals. Due to more intensive water rock interactions including the ore minerals, the mine water concentrations of main components and trace metals are generally higher compared to non mining affected surface waters of the mountain range. Furthermore, the content of major ions in mine water is enriched by mixing processes with saline waters from Permian layers in the Kupferschiefer district and at the deeper levels of the mines in the Upper Harz Mountains. The waters of the different mining districts can be distinguished by trace metal occurrences and concentrations derived from the different ore bodies. Water from the Kupferschiefer mines shows the highest Na, Cl, Cu, Mo and U concentrations, whereas a combination of elevated As and Se concentrations is typical for most of the samples from the mines around St. Andreasberg. However, there are exceptions, and some water samples of all the investigated mining districts do not follow these general trends. Despite the influence of mining activities and ore mineralisation, hydrochemical effects due to rain water dilution can be seen in most of the waters. According to the elevation of the mountain range, higher precipitation rates decrease the ion concentrations in the waters of springs, creeks and mine adits.     

Mineralogical and geochemical signature of mine waste contamination, Tresillian River, Fal Estuary, Cornwall, UK

The mineralized district of SW England was one of the world's greatest mining areas, with mining commencing in the Bronze age, peaking in the 1850s to 1890s, but still continuing to the present day. Consequently, it is not surprising that mining has had a major impact on the environmental geochemistry of SW England. In this study, the mineralogical and geochemical signature of mine waste contamination within the Fal Estuary at Tresillian, Cornwall, has been examined. A pulse of mine waste contamination is recognized at approximately 50?cm below present day sediment surface. Sn, As, Cu, Pb, and Zn are all enriched within this contaminated interval with up to 1800 mg?kg^–1 Sn, 290 mg?kg^–1 As, 508 mg?kg^–1 Pb, 2210 mg?kg^–1 Zn, and 1380 mg?kg^–1 Cu. Within this interval, the dominant minerals present include chalcopyrite, arsenopyrite, pyrite, cassiterite, Fe–Ti oxides (ilmenite and ?rutile), wolframite, sphalerite, baryte, zircon, monazite, tourmaline and xenotime. In addition, man-made slag products commonly occur. The exact timing of the release of mine waste into the estuary is poorly constrained, but probably occurred during or immediately following the peak in mining activity in the nearby Camborne-Redruth district, which was between 1853 and 1893. The mine waste may have entered the estuary either via the Tresillian River and its tributaries or via Calenick Creek and the Truro River and/or the Carnon River which flows into Rostronguet Creek.     

Mercury pollution from artisanal mercury mining in Tongren, Guizhou, China

Concentrations of total Hg (T-Hg) were measured in mine waste, stream water, soil and moss samples collected from the Tongren area, Guizhou, China to identify potential Hg contamination to local environments, which has resulted from artisanal Hg mining. Mine waste contained high T-Hg concentrations, ranging from 1.8 to 900 mg/kg. High concentrations of Hg were also found in the leachates of mine waste, confirming that mine waste contains significant water-soluble Hg compounds. Total Hg distribution patterns in soil profiles showed that top soil is contaminated with Hg, which has been derived from atmospheric deposition. Data suggest that organic matter plays an important role in the binding and transport of Hg in soil. Elevated T-Hg concentrations (5.9–44 mg/kg) in moss samples suggest that atmospheric deposition is the dominant source of Hg to local terrestrial ecosystems. Concentrations of T-Hg were highly elevated in stream water samples, varying from 92 to 2300 ng/L. Particulate Hg in water constituted a large proportion of the T-Hg and played a major role in Hg transport. Methyl–Hg (Me–Hg) concentrations in the water samples was as high as 7.9 ng/L. Data indicate that Hg contamination is dominantly from artisanal Hg mining in the study area, but the extent of Hg contamination is dependent on the mining history and the scale of artisanal Hg mining.     

Sulphide-mining impacts in the physical environment: Sierra de Cartagena–La Unión (SE Spain) case study

The environmental impact and potential-risk assessment of an abandoned sulphide-mining site in a semiarid climate is presented here, by the study case of Sierra de Cartagena–La Unión (SE Spain), a 2,500-year-old mining district extending over an area of 100 km². The regional map illustrates the existence of 12 open-pits, 1,902 mining wells, 2,351 waste deposits, including 89 tailing dams and waste rock derived from mining processes. Mine wastes occupy an area of 9 km² and have an approximate volume of 200 Mm³. Mineralogical, physical and chemical data distinguish nine different types of mine and metallurgical waste. According to the concentration of sulphate and heavy metals in sediment, soil, rainwater, surface water and groundwater samples, it is possible to conclude that the impact of mine activities occurs not only in the immediate mining area (100 km²), but also in the surrounding areas (an affected area of 1,000 km² approximately). The hydrochemical data show that groundwater, runoff water and some rainwater samples exceed Spanish and European water quality guideline values for water supply. The main geochemical process recognised is sulphide-mineral oxidation and later-generated sulphate dissolution by groundwater and runoff. Runoff and wind are the major mechanisms of metals and sulphate transport in the study area and adjacent zones.     

四川省会理县拉拉地区铜矿山开发生态环境影响评价

本文对四川省拉拉铜矿矿区噪声、水质、土壤、大气等各方面的检测数据进行了分析,阐述了矿区的主要环境地质问题：矿区家属区噪声污染较严重,选矿厂附近大气污染集中在,水质污染主要源于尾矿库渗透;并提出了矿区环境保护建议。     

矿山地质环境影响评价及修复研究——以汶川某废弃露天矿山为例

矿山正常的生产经营活动势必形成一定的矿山地质环境问题。为全面贯彻生态文明思想,牢固树立“绿水青山就是金山银山”的理念,按照恢复生态、兼顾景观总体要求,因地制宜、多措并举,扎实开展废弃露天矿山地质环境修复。依据矿山地质环境保护与恢复的相关规范与要求,以汶川某废弃露天矿山为例,从矿山环境角度介绍了矿山地质环境的影响因素,开展矿山斜坡整体稳定性、采场边坡稳定性、弃渣堆稳定性及地形地貌景观破坏等地质环境影响评价,划分治理重点、次重点和一般3个基本的矿山地质环境保护与恢复防治区。结果表明: 矿山斜坡及弃渣堆现状基本稳定、采场边坡稳定性较差、地形地貌景观影响和破坏程度中等; 研究区矿山地质环境保护与恢复治理可划分为一般防治区和较严重防治区,其中一般防治区面积约554 m²(矿区无因采矿活动诱发的地质灾害,影响区内无居民居住,无威胁对象,矿区及周围地表水体未漏失,矿业活动对水土环境影响程度为影响程度小,未影响到矿区及周围生活供水)、较严重防治区面积186 m²(矿区与影响区地质灾害发生可能性小,地形地貌景观影响和破坏程度较严重)。针对评价结果提出的“坡面浮石清理+清除建筑垃圾、块石+植被重建”等修复建议,为同类型矿山绿色开采及地质环境保护措施提供了的重要技术参考依据。     

The distribution of heavy metals in an abandoned mining area; a case study of Strauss Pit, the Drake mining area, Australia: implications for the environmental management of mine sites

Surface water samples from the Drake mining area show elevated metal concentrations, notably cadmium, iron and zinc. A detailed study of a sphalerite /quartz vein from Strauss Pit and chalcopyrite and pyrite from the Adeline mine and Strauss Pit indicate that micro-scale analyses of ores are necessary for environmental management of mine sites. Analyses show that Cd is elevated, up to 2.1 % by weight, and is associated with sphalerite, replacing Zn, or to a lesser extent replacing Pb within small galena grains. High concentrations of Cu are also associated with the Strauss Pit ore as small chalcopyrite grains along the margins of the sphalerite vein, within the central quartz zone of the vein system, and as replacement rims on sphalerite grains. Chalcopyrite from the Adeline mine area, is by comparison, metal poor, but still contains elevated heavy metal concentrations. Whereas, pyrite and chalcopyrite, from Strauss Pit have variable heavy metal concentrations, with chalcopyrite from within sphalerite veins having higher Cd and Zn concentrations than chalcopyrite distal to the veins. Cadmium and other heavy metals within the ores are mobilised during sulphide weathering and enter the drainage network; precipitation of secondary oxidation minerals act as temporary stores for many heavy metals. The complexity of the mineral and heavy metal associations at Strauss Pit suggest that a detailed knowledge of these associations and distributions within ore bodies, and associated waste rocks, are needed by environmental managers of mine sites because the presence of havy metals may greatly affect the decision making process, and management strategies employed. Received; 14 July 1999 · Accepted: 17 August 1999     

Environmental geochemistry of the derelict Webbs Consols mine,New South Wales,Australia

Small-scale mining and mineral processing at the Webbs Consols polymetallic PbZnAg deposit in northern New South Wales, Australia has caused a significant environmental impact on streams, soils and vegetation. Unconfined waste rock dumps and tailings dams are the source of the problems. The partly oxidised sulphidic mine wastes contain abundant sulphides (arsenopyrite, sphalerite, galena) and oxidation products (scorodite, anglesite, smectite, Fe-oxyhydroxides), and possess extreme As and Pb (wt% levels) and elevated Ag, Cd, Cu, Sb and Zn values. Contemporary sulphide oxidation, hardpan formation, crystallisation of mineral efflorescences and acid mine drainage generation occur within the waste repositories. Acid seepages (pH 1.9–6.0) from waste dumps, tailings dams and mine workings display extreme As, Pb and Zn and elevated Cd, Cu and Sb contents. Drainage from the area is by the strongly contaminated Webbs Consols Creek and although this stream joins and is diluted by the much larger Severn River, contamination of water and stream sediments in the latter is evident for 1–5 km, and 12 km respectively, downstream of the mine site. The pronounced contamination of local and regional soils and sediments, despite the relatively small scale of the former operation, is due to the high metal tenor of abandoned waste material and the scarcity of neutralising minerals. Any rehabilitation plan of the site should include the relocation of waste materials to higher ground and capping, with only partial neutralisation of the waste to pH 4–5 in order to limit potential dissolution of scorodite and mobilisation of As into seepages and stream waters.     

矿产资源开发中矿山地质环境问题响应差异性研究——以陕西潼关、大柳塔及辽宁阜新矿区为例

以陕西潼关、大柳塔及辽宁阜新矿区为例,采用对比分析的方法研究矿产资源开发中矿山地质环境问题差异性响应的主要因素。上述3个矿区矿产资源开发中矿山地质环境问题主要包括：20世纪90年代以前,陕西潼关金矿区是中国矿产资源开发秩序十分混乱的矿区之一,地下开采的采矿废石随意堆排导致了极为严重的矿山泥石流地质灾害及其隐患,＂三废＂无序排放导致土壤、河水及其底泥的重金属及氰化物污染严重,严重影响人体健康;地处生态环境脆弱带的陕西大柳塔煤矿区,20年大型机械化地下煤炭资源开采导致大面积地面塌陷及其链生的地下水含水层破坏严重,但矿区土地沙漠化程度总体没有呈现加重的趋势,水土环境重金属呈轻度污染;具有百年开发历史的辽宁阜新煤矿区,露天开采使土地生态破坏严重、边坡滑坡灾害频发、土地压占与破坏突出,地下开采引起的地面塌陷对地表建筑物及人居安全影响严重,但相对于金属矿区,该矿区水土环境重金属污染相对轻得多。对比上述3个矿区矿山地质环境问题,得到其差异性响应主要因素：矿产资源种类、原生地质环境条件、开采方式及矿山环境保护意识等。     

河南荥巩矿区岩溶水发育规律研究

通过对矿区地层、构造以及水文地质条件的分析,认为寒武-奥陶系岩溶裂隙含水层是矿区的主要含水层。岩溶水受地层岩性、构造的作用明显,岩溶发育程度在矿区呈现出西弱东强,浅部强、深部弱的发育规律。岩溶水动态受大气降水和矿井排水的双重控制,大气降水是岩溶水的主要补给来源,矿井排水是主要排泄方式,水位动态属于降水-矿排型。在天然状态下,岩溶水主要接受南部露头区大气降水的补给,然后自南向北、自西向东径流,经过新中-三李一带的岩溶水强径流带,在三李一带以岩溶大泉的方式向外排泄。     

Assessing the acidic potential of waste rock in the Akara gold mine,Thailand

Acid mine drainage (AMD) is the environmental issue that generates the greatest public concern regarding the mining industry. Thus, characterization of mine waste rock according to acid generation potential is necessary for mining operations to ensure proper waste rock storage and to avoid future adverse environmental effects. Therefore, this study was conducted to estimate the potential of AMD generation in the largest operating gold mine in Thailand by using acid base accounting and net acid generation tests. Representative samples of six types of waste rock classified by mining geologists for mineral processing and waste dumping were collected for this study: volcanic clastic, porphyritic andesite, andesite, silicified tuff, silicified lapilli tuff, and sheared tuff. Under various conditions, experimental results indicate that only silicified lapilli tuff and shear tuff are potentially acid-forming materials. The results indicate that AMD generation may possibly occur a long time after mine closure due to the lag time of the dissolution of acid-neutralizing sources. Acidic generation from some waste rocks may occur in the future based on environmental conditions, particularly the oxidation of sulphide minerals by the combination of oxygen and water. Therefore, a proper design for waste rock dumping and storage is necessary to reduce the risk of AMD generation in future. It is advisable to install a surface management system to control the overland flow direction away from the waste dump area and tailing storage facility and to install a second water storage pond next to the main storage pond to store the spilled water during storms and the rainy season. A water quality monitoring plan that focuses on disturbed areas such as water storage ponds and mine pits should be put in place.     

基于高分卫星遥感数据的金属矿开发现状及环境问题研究——以江西省德兴多金属矿集区为例

为及时、准确地掌握金属矿山的开发状况,有针对性地对金属矿山开发引起的环境问题进行恢复治理,以ZY-3等高分辨率卫星遥感数据为信息源,对江西省上饶市德兴多金属矿集区金属矿的开采状况及引发的环境问题进行了研究。在广泛收集矿区地质矿产资料、地形资料和遥感资料的基础上,结合露天开采、地下开采、联合开采等不同开采方式的金属矿的影像特征和实地调查验证,建立了金属矿开发占地的直接和间接解译标志; 根据各类矿山地物的影像特征和解译标志,对研究区金属矿山开采情况和环境状况进行目视解译和人机交互解译,获取了研究区内各时相的矿山开发状况和环境状况信息; 利用ArcGIS平台中空间分析模块功能对各类开发占地的面积进行了统计分析; 根据统计数据对研究区的金属矿开采状况及其诱发的地质灾害、植被破坏、污染水体和固体废弃物等矿山环境问题进行分析,指明研究区矿山环境问题的研究现状及发展趋势,有针对性地提出建议,为矿山环境监测和矿山环境恢复治理工程提供参考依据。     

Ephemeral acid mine drainage at the Montalbion silver mine,north Queensland

Sulfide‐rich materials comprising the waste at the abandoned Montalbion silver mine have undergone extensive oxidation prior to and after mining. Weathering has led to the development of an abundant and varied secondary mineral assemblage throughout the waste material. Post‐mining minerals are dominantly metal and/or alkali (hydrous) sulfates, and generally occur as earthy encrustations or floury dustings on the surface of other mineral grains. The variable solubility of these efflorescences combined with the irregular rainfall controls the chemistry of seepage waters emanating from the waste dumps. Irregular rainfall events dissolve the soluble efflorescences that have built up during dry periods, resulting in ‘first‐flush’ acid (pH 2.6–3.8) waters with elevated sulfate, Fe, Cu and Zn contents. Less‐soluble efflorescences, such as anglesite and plumbojarosite, retain Pb in the waste dump. Metal‐rich (Al, Cd, Co, Cu, Fe, Mn, Ni, Zn) acid mine drainage waters enter the local creek system. Oxygenation and hydrolysis of Fe lead to the formation of Fe‐rich precipitates (schwertmannite, goethite, amorphous Fe compounds) that, through adsorption and coprecipitation, preferentially incorporate As, Sb and In. Furthermore, during dry periods, evaporative precipitation of hydrous alkali and metal sulfate efflorescences occurs on the perimeter of stagnant pools. Flushing of the streambed by neutral pH waters during heavy rainfall events dissolves the efflorescences resulting in remobilisation and transport of sulfate and metals (particularly Cd, Zn) downstream. Thus, in areas of seasonal or irregular rainfall, secondary efflorescent minerals present in waste materials or drainage channels have an important influence on the chemistry of surface waters.     

An experimental study of water–rock interaction and acid rock drainage in the Butte mining district,Montana

. This paper summarizes a laboratory study of water–rock interaction and the generation of acidic mine drainage in the Butte mining district, Montana. The Butte district includes two large open pit mines exploiting different portions of the same porphyry Cu–Mo system: (1) the well-known Berkeley Pit, which is abandoned and flooding with acidic mine water; and (2) the nearby Continental Pit, which is active. The two pits are separated by a normal fault with several thousand feet of vertical displacement, and consequently the styles of alteration and mineralization are quite different. Humidity cell and recirculating leachate experiments of crushed rock exposed on the walls of the Berkeley Pit produced effluent waters very similar in composition to the flooded Berkeley Pit lake. In contrast, the same experiments on crushed ore from the Continental Pit generated circum-neutral leachates with low metal concentrations, caused by the presence of calcite in the alteration assemblage. Because carbonate is being depleted at a faster rate than pyrite during weathering, the quality of mine drainage in the Continental Pit could eventually degrade.     

Arsenic content and groundwater geochemistry of the San Antonio-El Triunfo, Carrizal and Los Planes aquifers in southernmost Baja California, Mexico

 The San Antonio-El Triunfo mining district, located at a mountainous region 45 km south-east of La Paz, Baja California, has been worked since the late 1700s. Mine waste material produced during 200 years of mineral extraction area poses a risk of local groundwater pollution and eventually, regional pollution to the Carrizal (west basin) and the Los Planes (east basin) aquifers. There are different types of deposits in the mining area. These are dominated by epithermal veins, in which arsenopyrite is an important component. Carrillo and Drever (1998a) concluded that, even though the amount of mine waste is relatively small in comparison to the large scale area, significant As in groundwater derived from the mine waste piles is found locally in the groundwater. This paper shows the results of geochemical analyses of groundwater samples from the San Antonio-El Triunfo area and the Carrizal and Los Planes aquifers during several years of monitoring (1993–1997). The highest values of total dissolved solids (TDS) and As are in the mineralized area where the mining operations occurred (∼1500 ppm TDS and 0.41 ppm As). The lowest concentrations of TDS and As are, in general, away from the mineralized area (∼500 ppm TDS and 0.01 ppm As). Sulfate and bicarbonate (alkalinity) are, in general, high near the mineralized area and low away from it. The arsenic concentrations vary seasonally, especially after the heavy summer thunderstorms. Geochemical modeling (MINTEQA2 and NETPATH) and analysis of the regional geochemical evolution of the groundwater from the mining area towards the aquifer of Los Planes shows that the most likely hydrochemical processes include: dilution, precipitation of calcite, and adsorption of As onto surfaces of iron oxyhydroxides (ferrihydrite). These processes act as natural controls to the extent and amount of As pollution in the Carrizal and Los Planes aquifers. Received: 4 May 1999 · Accepted: 22 February 2000     

铜陵矿区主要河流水质分析与污染评价

铜陵矿区是长江下游重要的铜铁资源基地,也是典型的含硫多金属矿区,矿山酸性废水是矿业开发活动不可避免的环境问题,对地表水体有很大影响。本文以铜陵矿区主要河流为研究对象,通过野外调查采样和室内测试分析,从常规理化性质、矿山酸性废水和重金属元素三方面分析了的水质现状,采用单因子指数和内梅罗水质指数法进行了污染评价。结果表明:(1)矿区河流污染成分以有机污染和矿山酸性废水污染为主,其次是重金属污染。(2)在检测的46个河段中, 按综合污染指数大小分级,共计有93.48%的河段受到不同程度的污染,其中,水质严重污染的河段占 4.35%,水质重污染的河段占13.04%,水质污染的河段占 65.22%,水质轻污染的河段占10.87%;共计有6.52%的河段水质较好,均为清洁状态。(3)3条河流按污染程度大小依次为新桥河>顺安河>红星河,除顺安河外,其他均受到了矿山酸性废水污染。今后应重点关注矿山酸性废水的污染机理与风险评估,加强矿区水环境保护与恢复治理工作。     

硫多金属矿床开采对水环境的影响——以福建大田地区矿产开发为例

闽西大田地区矿床采选冶活动对水土生态环境系统造成了严重的破坏，矿区采选矿废水pH值、SO4^2-浓度远远超过水环境标准，选矿废水和接纳采选矿废水的河流水体中Fe、Mn、Cu、Pb、Zn、Cd的含量大部分超过地面5类水标准，少部分超过4类水标准，矿区采选矿业废水是地表水金属污染的重要源头。矿业废水pH值与金属Fe、Mn、Cu、Pb、Zn、Cd的含量具有明显的负相关关系，SO4^2-浓度与金属离子Fe、Mn、Cu、Pb、Zn、Cd浓度具有较一致的变化规律。提出整治硫多金属矿山环境污染，应坚持因地制宜、矿业资源开发与环境保护并重的方针，用石灰石碱性中和酸性废水，隔离覆盖尾矿矿堆，对废弃矿山植树种草进行生态修复，对效益低下的开采矿山退矿还林，对严重环境污染的矿山实行关闭，对新开矿山要进行科学规划开发。     

Geochemical hazard evaluation of sulphide-rich iron mines: The Rio Marina district (Elba Island,Italy)

Rio Marina mining district (Elba Island) is characterised by hematite + pyrite ore association and was exploited for iron till 1981, leaving waste rock dumps of several millions m³. The effect of open pit mining activity in this site is to produce acid mine drainage (AMD) processes leading to environmental pollution, testified by all the sampled waters (Giove stream, drainage channels, superficial pools and settling basin) which have pH values ranging from 2.08 to 3.35 and heavy metal concentrations that reach 903.16 mg/l for Fe, 45.02 mg/l for Mn, 10.08 mg/l for Zn and 1.75 mg/l for Cu. In the present work a space and time related approach to geochemical hazard evaluation was applied. The geochemical hazard is mainly related to high heavy metal concentration, acid mine drainage processes development and topographic setting. As all these parameters are related in space, hazard evaluation was performed by geostatistical methods. Fifty-four earth material samples (residual soils, waste rocks or debris materials) were collected in a central aligned 100 m mesh square grid. These were analysed for major elements by XRF, for Cu, Pb, Zn by ICP-AES and for AMD potential following the AMIRA procedure. The concentration of heavy metals was compared with Italian law limits. The overlap of Cu, Pb and Zn content maps show that at least one of these heavy metals exceed law limits in all the area. The AMD test results show that more than 50% of samples have a positive NAPP (Net Acid Producing Potential) that could reach 258.9 kg H₂SO₄/t. According to the obtained data, three main geochemical hazard classes were established and their distribution in the mining area was assessed. About 51% of the mining area surface belongs to the major hazard class, where AMD process occurs, about 49% belongs to an intermediate hazard class, where AMD process could occur only if certain conditions are met. Finally, the persistence of the AMD process in the Rio Marina area was evaluated on the basis of yearly rainfall, mining waters pH and NAPP values. A complete leaching of the first 0.25 m of the earth materials can retain the current environmental conditions for several centuries.