Source Protection Area Research Articles

Contamination of neonicotinoid insecticides in source water and their fate during drinking water treatment in the Dongguan section of the Pearl River

Neonicotinoid insecticides (NEOs) as well as their metabolites are highly mobile on the subsurface and can potentially contaminate drinking water sources; however, their pollution status and fate in the drinking water system remains ambiguous. In this study, six parent NEOs and two characteristic metabolites were measured in drinking water source protection area (source water, n = 52) and two related drinking water treatment plants (DWTPs) (n = 88) located in the Dongguan section of the Pearl River. The ubiquitous of NEOs was observed in source water with the mean concentration of total NEOs (ΣNEOs) at 240 ng/L. Although advanced DWTP (A-DWTP; range: 26 % to 100 %) showed better removals of ΣNEOs and all individual NEOs rather than those in conventional DWTP (C-DWTP; range: −53 % to 28 %), the removals were still low for acetamiprid (ACE, 26 %), thiacloprid (THD, 59 %), thiamethoxam (THM, 56 %) and N-desmethyl-acetamiprid (N-dm-ACE, 45 %) in A-DWTP. Removal rates were positive in chlorination (48 %), final stage of sedimentation (F-Sed, 24 %), and granular activated carbon (GAC) filter effluent (19 %) in A-DWTP. It worthy to note that ΣNEOs has high negative removal rates at the start stage of sedimentation (S-Sed, −83 %), middle stage of sedimentation (M-Sed, −47 %), and sand filter effluent (−42 %) water in C-DWTP, which resulted in negative removals of ΣNEOs (−9.6 %), imidacloprid (IMI, −22 %), clothianidin (CLO, −37 %), flupyradifurone (FLU, −76 %), and N-dm-ACE (−29 %) in C-DWTP. Residual levels of NEOs were high in source water, and their low or negative removals in DWTPs should be highly concerning. Results would fill the existing knowledge gap of NEOs in aquatic environment and provide a scientific dataset for policy-making on pollution control and environmental protection.

Numerical study of hydraulic fracturing in the sectorial well-factory considering well interference and stress shadowing

In the Changqing Oilfield in northwest China, when traditional petroleum exploitation encounters forestry reserves or water source protection areas, sectorial well-factory design is proposed. The most distinct feature of a sectorial well-factory is the deviation of the well from the minimum horizontal principal stress, resulting in hydraulic fracture deflection after the initiation, along with possible well interference (i.e., fracture hit) and fracture coalescence in the oblique wells. Four indexes describing well deflection are then proposed according to fracture morphology. Several fracturing designs, including stage arrangement, fracturing sequences, and fracturing techniques are applied to study the feasibility of the sectorial well-factory design. The results show that the “gradual” or “sparse” stage arrangement, large injection rate, and simultaneous multifracture treatment can help to optimize the fracture morphology and stimulation design. However, the subsequent stress shadowing effect usually adversely affects the fracturing of adjacent wells. With a small initial horizontal stress difference, large injection rate and staggered stage arrangement can achieve ideal stimulation performance. Our results can provide a guidance for optimizing stimulation design in unconventional well-factory while taking into account environmental protection.

Application Study of MIKE11 in Meiliang Lake Water Transfer Experiment

In order to strengthen the scientific and technological research work of cyanobacteria control in Taihu Lake, the "Taihu (Meiliang Lake) water transfer on the control of cyanobacteria, improve lake water quality" project declared by Wuxi Hydraulic Society was approved by the municipal Association for Science and Technology. By further studying the effect of pumping station water transfer on controlling cyanobacteria and improving the water quality of Meiliang Lake, it is of great practical significance to implement the comprehensive water environment management of Taihu Lake basin and give full play to the ecological and social benefits of Taihu Lake. This project mainly through the pump station water transfer test work, synchronously monitoring wind direction, water level, flow, water quality (dissolved oxygen, total phosphorus, total nitrogen, permanganate index, algae density, etc.) data, combined with the waterway section data measured in advance to prepare a river network file, reasonably determine the simulation calculation range, determine the boundary conditions and calculation period. MIKE11 hydrodynamic model and water quality convection and diffusion model were adopted for simulation calculation and analysis, and model verification was carried out, achieving ideal simulation results. The analysis showed that the water transfer test had little effect on pollutant concentration, and the comprehensive evaluation category of Meiliang Lake water quality did not change, still classified as V ~ poor V, and the main items exceeding the standard were total phosphorus and total nitrogen. During the experiment period of 8 days, the water transfer reduced the permanganate index by 147 tons, the total phosphorus by 5 tons, the total nitrogen by 42 tons, and the algal density by 2.45 million cells /L. If the water transfer rate of Meiliang Lake pumping station is 60 m³/s and that of Dashihe Pump station is 30 m³/s, the permanganate index of Meiliang Lake can be reduced by 440 tons, total phosphorus by 16 tons and total nitrogen by 119 tons, and the algae density can be reduced by 4.28 million cells /L. The water transfer increased the water flow speed of Meilang Lake, increased the self-purification capacity of the lake body, greatly reduced the water pollutants in Wuxi Taihu Lake key water source protection area and sightseeing area, and reduced the density of algae.

Country Parks as Sites of Emergency Medical Facility: A Case of COVID-19 in Hangzhou, China.

City parks are suitable sites for the construction of emergency medical facilities. A comparison of various types of city parks revealed that country parks fit closely with site selection conditions for emergency medical facilities. Based on the latter site selection requirements, eight impact factors such as park type, effective avoidance area, spatial fragmentation degree, water source protection area, wind direction, distance from city center, impermeability, and transport duration were quantified, and then 29 country parks in the Hangzhou Urban Area were compared using Principal Component Analysis (PCA). The calculation results showed that Linglong Country Park has the highest score, taking into account the characteristics of safety, scalability, rehabilitation, convenience, pollution prevention, and isolation. Linglong can be given priority selection as a target location for emergency medical facilities. In addition, Silver Lake Country Park, Dongqiao Country Park, Taihuyuan Country Park, and Tuankou Country Park have higher scores and can be used as alternative targets for emergency plans. The scoring results prove that the evaluation method has a high degree of rigor, a significant degree of discrimination, and a high degree of consistency between the validity and weight assignment of each impact factor. In view of the different geographical conditions in each region, the weight assignment of each impact factor can be adjusted according to local conditions and can help make effective use of existing conditions and avoid disadvantages.

The assessment of ecological restoration effects on Beijing-Tianjin Sandstorm Source Control Project area during 2000–2019

To halt the trend of desertification and improve the ecological environment in Beijing, Tianjin and surrounding areas, China establishes the ecological engineering of Beijing-Tianjin Sandstorm Source Control Project. The assessment of ecological restoration after the implementation of ecological engineering is conducive to the ensuing management of ecological engineering. Based on a large number of remote sensing data and calculation models, this study selected land use/cover, vegetation ecological quality indicators such as vegetation coverage and NPP, and other ecological service indicators such as water retention calculated by the InVEST model, soil retention by the RUSLE model, and sand fixing services by RWEQ model to comprehensively assess the degree of restoration and trend of ecological engineering implementation. The contributions of climate change and human activities to NPP and soil retention services are also assessed. We found that from 2000 to 2019, the land cover pattern is optimized, with desert and farmland turning to grassland and forest. The vegetation ecological quality has been improved, sand-fixing service have been significantly improved, and water retention and soil retention service are degraded in some areas. The areas with a high-degree restoration are mainly located in the water source protection areas in the Yanshan mountainous region and in some areas in the south-eastern Horqin Sandy Land, while the areas with a low-degree restoration are mainly located in the desert grassland. The ecological improvement areas are mainly distributed in the mountains in norther Shanxi Province, the water source protection area in the Yanshan mountainous region, the Southern Great Hinggnan Mountains and part of the agro-pastoral transitional grassland. The highly degraded areas are mainly concentrated in the middle of Horqin and Otindag Sandy Lands. Ecological engineering plays an important role in promoting ecological restoration by changing land use types. The contribution proportion of climate change to NPP and soil retention services are significantly higher than those of human activities. The degree of ecological restoration depends on the climax ecological background determined by the climate.

Occurrence and Risk Assessment of per- and Polyfluoroalkyl Substances in Water Source Protection Area of Southeastern China

In order to clarify the pollution characteristics and human health risks of PFASs pollutants in typical drinking water sources in Zhejiang Province, this study relies on ultra -performance liquid chromatography-mass spectrometry (UPLC-MS/MS) technology to analyze the pollution of 26 PFASs in 7 reservoirs in Zhejiang Province. The detected concentrations of PFASs were evaluated to further assess the human health risks. Total PFASs concentrations in the seven reservoirs ranged from 1.30 ng L−1–24.90 ng L−1. Among the 26 PFASs pollutants analyzed, PFOA and PFBA were the main PFASs pollutants, the detected concentrations of PFOA and PFBS ranging from 0.50 ng L−1–13.70 ng L−1 and 0 ng L−1–1.70 ng L−1, respectively. Then we evaluated 15 PFASs and calculated the results of the HQ value of the reproductive toxicity and hepatotoxicity of the total PFASs in this study ranged from 2.30 × 10–8 to 1.16 × 10–4 and 9 × 10–8 to 5.24 × 10–4 respectively, which were both lower than 0.01, indicating that there is no significant risk to the human body.

Design of Constructed Wetland Treatment Measures for Highway Runoff in a Water Source Protection Area

Road runoff contains high levels of pollutants, such as heavy metals and hydrocarbons. If they are directly discharged into sensitive water bodies, they will cause irreversible pollution and damage to the water environment. Furthermore, the leakage of hazardous chemicals into sensitive waters will lead to serious consequences, so determining how to deal with road surface runoff has become an urgent problem. This research adopts a scheme for collecting and processing road runoff in a water source protection area using artificial wetlands. After optimizing and improving the general vertical flow of the wetland structure, a composite wetland structure and a relatively novel tandem wetland structure are proposed. An indoor model is established for experiments on various main wetland structure schemes. The results show that the two newly proposed wetland structures improve the possibility of water level control in general vertical flow structures. At the same time, the movement distance of the water flow in the wetland structure is changed to improve the treatment effect of runoff. The removal effect of composite and tandem wetland structures for heavy metals, petroleum substances, and COD (chemical oxygen demand) is significantly better than that of general vertical flow structures. Among them, the composite structure is better than the tandem structure at removing heavy metals, petroleum substances, and COD. However, due to the water discharge method of the structures, the latter has a better effect than the former in the treatment of suspended substances.

Spatial scale effects of landscape patterns on water quality changes in drinking water source protection areas: a case study in the Guishui River Basin, China

Spatial scale effects of landscape patterns on water quality changes in drinking water source protection areas: a case study in the Guishui River Basin, China

How do You Want to restore?--Assessing the Public Preferences and Social Benefits of Ecological Restoration for Natural Rubber Plantation in China

Revealing the public’s preference for ecological restoration projects will help increase public support and improve social benefits evaluation accuracy, which is a prerequisite for implementing ecological restoration projects. This study aimed to reveal the public’s preference for natural rubber plantation restoration projects and then quantify the social benefits of these projects to provide valuable references for related policy design. Based on choice experiments, we built a hypothetical market of ecological products and conducted a field survey to obtain the public’s preferences and willingness to pay (WTP) for natural rubber plantation restoration projects. Then, a random parameters logit model was applied to obtain public preference information, and then the social benefits brought by different restoration scenarios were calculated and compared. The results showed that: 1) residents of Hainan Province had a positive attitude toward ecological restoration for natural rubber plantations and were willing to bear a personal cost. 2) respondents had significant differences in preference for attributes of restoration projects. 3) a restoration project covering 2.1 million mu of rubber plantations, prioritizing the water source protection area, focusing the implementation on state farms, and developing the under-forest breeding economy would gain more social benefits, precisely, 337.543 million yuan/year. Ecological restoration policies should pay more attention to public needs and incorporate them into future guidelines. Policymakers should focus on restoration quality instead of the restoration area. Priority should be given to rubber plantations close to the water source protection area and small householders, and an appropriate under-forest economy should be considered. This study can provide a valuable reference for policy-making related to rubber plantation restoration.

Research on the Non-Point Source Pollution Characteristics of Important Drinking Water Sources

In recent years, freshwater resource contamination by non-point source pollution has become particularly prominent in China. To control non-point source (NPS) pollution, it is important to estimate NPS pollution exports, identify sources of pollution, and analyze the pollution characteristics. As such, in this study, we established the modified export coefficient model based on rainfall and terrain to investigate the pollution sources and characteristics of non-point source total nitrogen (TN) and total phosphorus (TP) throughout the Huangqian Reservoir watershed—which serves as an important potable water source for the main tributary of the lower Yellow River. The results showed that: (1) In 2018, the non-point source total nitrogen (TN) and total phosphorus (TP) loads in the Huangqian Reservoir basin were 707.09 t and 114.42 t, respectively. The contribution ratios to TN export were, from high to low, rural life (33.58%), farmland (32.68%), other land use types (20.08%), and livestock and poultry breeding (13.67%). The contribution ratios to TP export were, from high to low, rural life (61.19%), livestock and poultry breeding (21.65%), farmland (12.79%), and other land use types (4.38%). The non-point source pollution primarily originated from the rural life of the water source protection zone. (2) Non-point source TN and TP pollution loads and load intensities showed significantly different spatial distribution patterns throughout the water source protection area. Specifically, their load intensities and loads were the largest in the second-class protected zone, which is the key source area of non-point source pollution. (3) When considering whether to invest in agricultural land fertilizer control or rural domestic sewage, waste, and livestock manure pollution control, the latter is demonstrably more effective. Thus, in addition to putting low-grade control on agricultural fertilizer loss, to rapidly and effectively improve potable water quality, non-point source pollution should, to a larger extent, also be controlled through measures such as establishing household biogas digesters, introducing village sewage treatment plants, and improving the recovery rate of rural domestic garbage. The research results discussed herein provide a theoretical basis for formulating a reasonable and effective protection plan for the Huangqian Reservoir water source and can potentially be used to do the same for other similar freshwater resources.

Evaluation of the value of water retention service in the middle and upper reaches of Hunhe River based on SWAT Model.

The upper and middle reaches of the Hunhe River, with forest coverage rate up to 68%, is an important water source protection area in Liaoning Province. Based on the SWAT model and shadow engineering method, we aimed to estimate the function and service value of water retention in the upper and middle Hunhe River basin from 2000 to 2019, to analyze the spatial heterogeneity, and to provide a scientific basis for the ecological compensation and ecological restoration of the region. Our results showed that the function and service value of water retention in the upper and middle reaches of the Hunhe increased first, and then decreased from 2000 to 2019. The mean annual amount and service value of water retention were 2.46 billion m3 and 15.04 billion yuan, respectively. The spatial distribution of water conservation service functions in the study area was uneven. The areas of high water retention service value were mainly distributed in Qingyuan County and Xinbin County, while the low-value areas were located in municipal districts of Shenyang City. The value of water retention services was obviously different among the ecosystems, with water retention capacity per unit area of forests being much higher than that of grassland, farmland, and cities.

Variation in fractional vegetation cover and its attribution analysis of different regions of Beijing-Tianjin Sand Source Region, China

Based on the MODIS NDVI data from 2000 to 2018, we estimated the fractional vegetation cover (FVC) using the dimidiate pixel model and analyzed the spatiotemporal characteristics of FVC in the Beijing-Tianjin sand source region (BTSSR). The geographical detector model was used to estimate the impacts of natural and human factors on FVC spatial distribution at the regional scale. The results showed that the FVC of the BBTSR showed an increasing trend from 2000 to 2018, with an annual growth rate of 0.013·(10 a)-1 and a vegetation increase rate of 8.2%. The area with high FVC was concentrated in the Yanshan Mountain water source protection area, followed by the pastoral transitional zone desertified land control area and the Otindag sandy land area. The area with poor FVC was concentrated in the northern arid grassland area. The explanatory power of driving factors to FVC varied across different regions. Among the natural factors, annual precipitation was the main driving factor for the spatial distribution of FVC in the northern arid grassland area, the Otindag sandy land area and the Yanshan Mountain water source protection area. Slope was the main driving factor for the spatial distribution of FVC in the pastoral transitional zone desertified land control area. Among different human activities, the number of large livestock at the year-end was the main driving factor controlling the spatial distribution of FVC in the northern arid grassland area and the pastoral transitional zone desertified land control area, while population density was the main driving factor controlling the spatial distribution of FVC in the Otindag sandy land area and the Yanshan Mountain water source protection area. There were regional differences in the influen-ce of other factors on FVC spatial distribution. The results of the interaction detector showed that the two-factor interactions were mainly the double-synergy and nonlinear synergy. The interaction of human activities with annual precipitation and slope could more fully explain the spatial variations of FVC. The range of suitable vegetation growth identified by the risk detector was the area with annual precipitation of 316.4-486.0 mm, average relative humidity of 48.4%-57.6%, and average annual temperature of 2.5-7.9 ℃, while other driving factors were different in different zones.

Further Discussion on the Influence Radius of a Pumping Well: A Parameter with Little Scientific and Practical Significance That Can Easily Be Misleading

To facilitate understanding and calculation, hydrogeologists have introduced the influence radius. This parameter is now widely used, not only in the theoretical calculation and reasoning of well flow mechanics, but also in guiding production practice, and it has become an essential parameter in hydrogeology. However, the reasonableness of this parameter has always been disputed. This paper discusses the nature of the influence radius and the problems of its practical application based on mathematical reasoning and analogy starting from the Dupuit formula and Thiem formula. It is found that the influence radius is essentially the distance in the time–distance problem in physics; therefore, it is a function of time and velocity and is influenced by hydrogeological conditions and pumping conditions. Additionally, the influence radius is a variable and is essentially different from the hydrogeological parameters reflecting the natural properties of aquifers such as the porosity, specific yield, and hydraulic conductivity. Furthermore, the parameterized influence radius violates the continuity principle of fluids. In reality, there are no infinite horizontal aquifers, and most aquifers are replenished from external sources, which is very different from theory. The stable or seemingly stable groundwater level observed in practice is simply a coincidence that occurs under the influence of various practical factors, which cannot be considered to explain the rationality of applying this parameter in production calculations. Therefore, the influence radius cannot be used to evaluate the sustainable water supply capacity of aquifers, nor can it be used to guide the design of groundwater pollution remediation projects, the division of water source protection areas, and the scheme of riverbank filtration wells. Various ecological and environmental problems caused by groundwater exploitation are related to misleading information from the influence radius theory. Generally, the influence radius does not have scientific or practical significance, but it can easily be misleading, particularly for non-professionals. The influence radius should not be used in the sustainable development and protection of groundwater resources, let alone in theoretical models. From the perspective of regional overall planning, the calculation and evaluation of sustainable development and the utilization of groundwater resources should be investigated in a systematic manner.

Spatiotemporal Change and Source Apportionment of Non-point Source Nitrogen and Phosphorus Pollution Loads in the Three Gorges Reservoir Area

The Three Gorges Reservoir area (TGRA) is a critical water source protection area in China and one of the regions with rapid economic development in the Yangtze River basin. Non-point source pollution is the leading cause of the deterioration of the water environment in the TGRA; therefore, studying the non-point source pollution status in the TGRA is of great significance to the regional ecological security and sustainable development. The improved export coefficient model was used to estimate the total non-point source nitrogen and phosphorus pollution loads in the TGRA from 1990 to 2015, the spatial and temporal characteristics of the non-point source nitrogen and phosphorus pollution were analyzed, and the primary sources of pollution were determined by calculating the contribution rate of each pollution source. The results concluded that the nitrogen and phosphorus pollution loads were highest in the hinterland of the reservoir, followed by the end of the reservoir, with the lowest in the head of the reservoir, showing significant spatial heterogeneity in the TGRA. The total loads of nitrogen and phosphorus pollution increased firstly and then decreased, which reached the highest value in 2000 and the lowest value in 2015. The contribution rate of each pollution source to the nitrogen and phosphorus pollution loads, from highest to lowest, were land use, rural life, livestock, and poultry farming. Among them, the land use type of dry land was the predominant source of non-point source nitrogen and phosphorus pollution.

Analysis of land use dynamics and driving forces of water source protection areas in the upper reaches of the Huangpu River

Analysis of land use dynamics and driving forces of water source protection areas in the upper reaches of the Huangpu River

Composition and Distribution Characteristics of Microplastics in Danjiangkou Reservoir and Its Tributaries

Microplastic pollution is a hot topic in environmental science. To explore the microplastics in Danjiangkou Reservoir, a national first-class water source protection area, we studied their types, abundance, and material characteristics using density flotation and micro-Raman spectroscopy. The spatial distribution characteristics of microplastics were also revealed according to the hydrologic and hydrodynamic conditions of the reservoir. The results showed that the main types of microplastics were fragments (84.2% of the total), granules, films, and fibers, of which 84.2% were fragments. The numbers of each type of microplastic were significantly different in different areas. A variety of colors were observed, with transparent and brown microplastic being most common. During the wet season, the average abundance of microplastics in the reservoir was 7248 n·m-3, which is higher than that observed in the Han Reservoir. The particle sizes of the microplastics in the research area ranged 75-4703 μm, of which 73.4% had a particle size of less than 500 μm; microplastic abundance was inversely related to particle size. Nylon was the most common form of microplastic in Danjiangkou Reservoir, accounting for 36.4% of the total, followed by polyethylene (PE) and polypropylene (PP).

Rainfall forecast of Tongjiqiao reservoir

The dam site of Tongjiqiao reservoir is located in Puyang River, a tributary of Qiantang River. Tongjiqiao reservoir is the backbone flood control water conservancy project in Puyang River Basin and an important source of ecological and environmental protection tourism. It is also a reserve water source protection area for the future development of Pujiang County. The reservoir not only provides most of the industrial and agricultural production and domestic water for several major towns (streets) and economic development zones of Pujiang County, but also undertakes the ecological water supply task of Puyang river. For a long time, Tongjiqiao reservoir has played an important role in the economic and social development of Pujiang County. In this paper, the model of adaptive neural fuzzy inference system is used to predict the rainfall of Tongjiqiao reservoir. The results show that the rainfall of the reservoir area is in the average level of many years from 2020 to 2025.

Comparison of Hydrological Model-Based and Geographical-Based Approaches for Estimating Water Travel Times for Source Water Protection

Many source water protection regulations simply define protection zones according to fixed geographical distances. A more precise approach would be to estimate water travel times from any point in the watershed to the drinking water intake, using a hydrological model in which watershed characteristics and hydrological regimes (dry, rainy) are taken into account. Is a data-intensive and, therefore, more precise approach really better than a simple geographical-based approach for source water protection? The aim of this paper is to present a methodology to compare a geographical-based approach for delimiting water source protection areas with a Soil and Water Assessment Tool (SWAT) hydrological model-based approach in terms of water travel times within a watershed. The watershed of the water treatment plant (WTP) in Quebec City (Canada) was used as a case study. Results reveal that implementing a geographical-based approach might be adequate to protect water intakes against non-point sources of contamination. However, in the event of point source contamination, the simpler approach is less appropriate, especially in a drought situation. SWAT results for four subwatersheds studied indicated that WTP operators would have less than 30 h to react to a point-source contamination event during a median rainy week and from 10 h to about 4 days during a dry week. The geographical-based approach, however, was unable to determine the effects of weather events on water travel times. The use of a hydrological-based model is, thus, more useful for the implementation of an emergency plan, based on weather events. • Characteristics of a watershed (area, land use, slopes and river length) and hydrological scenarios influence water travel times. • Delimiting a protection zone, a set distance from a water intake, can protect it against non-point sources of contamination. • Using a modelling approach allows the study of a wide range of technical and management scenarios that can be used to develop warning systems.

Capacity for source water protection in Ontario’s privately-serviced rural areas

This research examined the capacity for source water protection (SWP) of privately-serviced rural areas in Ontario. Privately-serviced areas refer to communities where households and public buildings either fully or partially derive their drinking water from private water systems (i.e. private wells), which are not serviced by a municipal drinking water system. Capacity for SWP in these areas was explored through a framework consisting of the following elements of capacity: technical/human, financial, social, and institutional. A case study approach was employed using the Cataraqui Source Protection Area and the North Bay-Mattawa Source Protection Area. Thirty key informant interviews were conducted and analyzed, together with a literature review and member checking. It was found that privately-serviced rural communities often do not see the protection of drinking water as one of their mandated responsibilities and that there are institutional, technical/human, social, and financial capacity gaps for undertaking SWP in privately-serviced areas. Further investigation is needed regarding options for a new, integrated, implementable and context appropriate SWP framework for privately-serviced areas in rural Ontario. The findings of this research provide transferable lessons for the creation of rural policy in general, and the need for a rural (rather than an urban focused) approach to policies and programs to protect rural drinking water.

Characterisation of fractured carbonate aquifers using ambient borehole dilution tests

Fractured carbonate aquifers derive their transmissivity essentially from a well-developed network of solutionally-enhanced fractures and conduits that can lead to high groundwater velocities and high vulnerability to contamination of water quality. Characterisation of the variation of hydraulic properties with depth is important for delineating source protection areas, characterising contaminant fate and transport, determination of the effectiveness of aquifer remediation, and parameter estimation for models. In this work, ambient open borehole uniform and point injection dilution tests were conducted on observation boreholes in the unconfined Cretaceous Chalk aquifer of East Yorkshire, UK, and interpreted in conjunction with other data via the implementation of a new work flow. This resulted in the characterisation of flow in these boreholes and the inference of properties such as groundwater flow patterns and velocities in the surrounding aquifer formation. Our workflow allowed sections of open boreholes showing horizontal versus vertical flow to be distinguished, and the magnitude of such flows and exchanges with the aquifer to be determined. Flow within boreholes were then used to characterise: i) presence and direction of vertical hydraulic gradients; ii) nature and depth distribution of flowing features; iii) depth interval porosity and permeability estimation of the flowing features from overall borehole transmissivity and geophysical image or caliper logs; iv) groundwater velocity estimation in the surrounding aquifer. Discrete flowing features were distributed across the range of depths sampled by the observation boreholes (typically up to 45–60 mbgl), but the majority were located in the zone of water table fluctuation marked by solutionally enlarged flow features. Quantitative interpretation of both uniform injection (tracer distributed throughout the open borehole section) and point injection (slug of tracer introduced at targeted depth) yielded vertical velocities within the borehole water column in broad agreement with those measured by flow logging. Depth specific fracture kinematic porosities inferred from the ambient dilution data combined with long-interval pump test and geophysical log data ranged between 3.7 × 10−4–4.1 × 10−3 with an average of 2.1 × 10−3; these values were in excellent agreement with those from other methods applied to the same aquifer such as larger scale pumping tests. A new approach to estimation of groundwater velocities from the dilution test data using externally measured hydraulic gradients gave inferred horizontal groundwater velocities ranging between 60 and 850 m/day, in full agreement with those from previously conducted borehole-to-borehole tracer tests. These results confirm that the studied aquifer is karstic, with rapid preferential pathways which have implication for flow and transport modelling, and pollution vulnerability. Our study results indicate that ambient single-borehole dilution approaches can provide an inexpensive and reliable approach for the characterisation of fractured and karstic aquifers.