INTRODUCTION
Water resources are essential for sustaining life, often referred to as the biological blood that nourishes both humans and ecosystems However, rapid population growth and socio-economic development have intensified the challenges of water resource management, leading to a concerning decline in both the quantity and quality of available water.
According to the Stockholm International Water Institute, approximately 2 million tons of domestic waste are released into rivers and seas daily, with 70% of untreated industrial waste being discharged directly into water sources in developing countries This dire situation contributes to inadequate sanitary conditions for half of hospitalized patients in these regions The lack of sanitation and clean water results in the deaths of over 1.6 million children each year Furthermore, the Food and Agriculture Organization (FAO) warns that nearly 2 billion people will face water scarcity, and two-thirds of the global population could experience dehydration within the next 15 years.
Vietnam is encountering significant challenges in water resource management, with upstream water quality appearing relatively good, while downstream conditions are deteriorating Pollution levels notably rise during the dry season due to reduced river water volumes.
A 2009 assessment report by the Government of Vietnam and its donors highlighted that water pollution poses a significant threat to the country's socio-economic development, impacting 9 million urban residents and 21 million rural inhabitants living near rivers.
Water pollution in urban areas of Vietnam, particularly in Hanoi and Ho Chi Minh City, has reached alarming levels These densely populated cities are experiencing a significant rise in the daily discharge of untreated domestic wastewater into surface water sources, exacerbating the pollution crisis.
Cau River, the primary river of the Thai Binh river system, originates from Van Ong Mountain and flows through key locations including Don Market in Bac Kan province and Moi Market in Thai Nguyen province, ultimately merging with the Thai Binh rivers at Pha Lai in Hai Duong This river is vital for the socio-economic development of seven provinces: Bac Kan, Thai Nguyen, Bac Giang, Bac Ninh, Vinh Phuc, Ha Noi, and Hai Duong.
The Cau River is crucial for providing water for hydropower and various socio-economic development activities However, recent studies indicate that the pollution levels in the river are rising, posing a serious threat to the water supply essential for the livelihoods of local communities.
The topic of this article is "Impacts of Socio-Economic Development Activities on the Water Quality of Cau River in Soc Son District, Ha Noi." The aim is to contribute to environmental protection and enhance the water quality of the Cau River in the study area.
Figure 1.1: Map of the study area [16]
GOALS AND OBJECTIVES
Goals
Through fact-finding, sampling and analyzing on Cau River water quality flowing through Tan Hung commune of Soc Son district, the thesis aims to figure out:
- Current status of Cau River water quality in Tan Hung commune, Soc Son district;
- Main activities affecting Cau River water quality.
Specific Objectives
- Analyze and assess Cau River water quality based on determined indicators; and comparing with National Technical Regulations;
- Evaluating the impacts of socio- economic development activities on Cau River water quality;
- Propose solutions to improve the effectivity of water management for Cau River flowing through Tan Hung commune, Soc Son district.
METHODS
Field investigation method
3.1.1 Preliminary investigations of study area
A preliminary investigation was conducted along a 7km segment of the Cau River in Tan Hung commune, Soc Son district, focusing on river sections that are influenced by various socio-economic activities.
After the preliminary investigation on the study area, causes have been identified causes affecting Cau River water quality flowing through Tan Hung commune, Soc Son district as following:
- Domestic wastewater and breeding from households living on the areas close to the river;
- Sand and gravel exploiting activities;
The thesis involved interviews conducted in five villages of the Tan Hung commune in Soc Son district, namely Ngo Dao, Dao Thuong, Coc Luong, Hieu Chan, and Cam Ha, all of which are situated along the Cau River.
The thesis planned to randomly release 300 questionnaires at five villages Therefore,
60 households have been interviewed at each village.
Assessment of Cau River water quality
Based on the purpose of research and analysis conditions, the thesis choosed the following indicators to analyze and assess:
- Physical indicators: pH, turbidity, temperature, content of suspended solids (TSS) and content of dissolved solids (TDS)
- Chemical indicators: DO (Dissolve Oxygen), BOD5 (Biological Oxygen Demand), and COD (Chemical Oxygen Demand)
The thesis focused on researching and sampling on Cau River sections flowing through Tan Hung commune as follows:
- Sampling locations: The locations or sources of pollution, impacting on water quality (waste, agricultural activities, exploiting activities )
The study involved three sampling sites at each location, including the middle of the river, 5 meters from the shore, and 1 meter from the shore Samples were collected at various depths at each site to ensure comprehensive data collection.
Surface water: Sampling at depths of 10- 20cm
Water in the middle depth: Sampling at depths follow the current depth
Bottom-water: Distance from the bottom of 10-15cm
The data of samples is filled into the table 3.1
[1]: sites of middle = 1; sites of 5m away from the shore = 2; sites of 1m away from the shore = 3
Table 3.1: Location of Cau river water sampled at some positions
No Sample names Location Sites [1] Depth(m) Coordinates ( 0
Sand and gravel exploiting activities
Sampling frequency: Identifying the sources of pollution to Cau River water quality, subsequently, taking samples at the sources as mentioned above Sampling at these locations on a monthly basis
Figure 3.1: Map of sampling sites [15]
Tools and methods used for sampling follows the standards:
TCVN 6663-1:2011 (ISO 5667-1: 2006) – Water quality- Sampling Part 1: sampling guides and techniques
TCVN 6663-3:2008 (ISO 5667-3:2003) – Water quality- Sampling Guidelines of sample preserving and processing
TCVN 6663-6:2008 (ISO 5667-6:2005) – Water quality - Sampling Sampling guidelines on rivers and streams
The thesis utilized a single sampling method aligned with its research objectives, involving the collection of a random water sample Subsequently, samples from the surface, middle, and bottom layers of water were combined at each site, leading to the implementation of a combinatorial sampling approach.
The Wild sampling tool, with a 2L capacity, is exclusively designed to collect water samples from various depths, utilizing a sample bottle that contains polymers for safe transport to the laboratory After the water sample is collected, it is crucial to securely seal the bottle with a lid to prevent any changes in the sample, particularly for dissolved oxygen (DO) analysis.
- Preserving and transporting of samples
To ensure accurate analysis, all bottled water samples must be cooled to approximately 4°C and promptly transported to the laboratory, where pH and temperature measurements are taken on-site For optimal preservation, samples should be stored in cool, dark environments, allowing them to remain viable for up to 24 hours.
- pH measurement method pH was measured by litmus paper through comparison of the color of litmus paper with the color table to determine the pH of water
Use a thermometer directly at the sampling location and record the results
The turbidity of the water samples was measured by fast measuring device as Micro TPI
- Analysis Method of Total Dissolved Solid (TDS)
The total dissolved solid of water was measured by fast measuring device as TDS Meter
- Analysis Method of Suspended Solids (TSS)
Suspended solids SS was calculated by the formula:
To determine the weight of the filter paper before and after filtration, measure the weight of the filter paper dried at 105 °C until a constant weight is achieved The initial weight, denoted as m1, is recorded after approximately 45 minutes of drying Following the filtration process, the weight of the filter paper, referred to as m2, is measured again after another 45 minutes of drying at the same temperature until a constant weight is reached.
- Methods for determination of BOD 5
The analyzed samples exhibited extremely high levels of BOD 5, necessitating dilution to an appropriate factor prior to testing To ensure accurate results, the water used for dilution was saturated with oxygen and supplemented with essential nutrients.
After diluting the sample, the initial Dissolved Oxygen (DO0) was measured at 20°C The sample was then incubated in a BOD-specific chamber at 20°C for five days Following the incubation period, the final Dissolved Oxygen (DO5) was re-measured, and the Biochemical Oxygen Demand (BOD5) was calculated in mg/L by subtracting the BOD5 values from the blank sample.
BOD 5 : BOD values after 5 days (mg/L)
DO 0 : DO values at 20 o C after diluting (mg/L)
DO 5 : DO values at 20 o C after 5 days incubating at 20 o C (mg/L) f: dilution factor
- Method for determination of COD ( Ferroin Indicator reagent)
- b is the volume of FAS (Ferrous Ammonium Sulfate) used in the blank sample
- s is the volume of FAS in the original sample
- n is the normality of FAS
The thesis used the following standards of Vietnam to assess the water quality at the study area:
- QCVN 38:2011/BTNMT: National technical regulation on Surface Water Quality for protection of aquatic lifes
- QCVN 39:2011/BTNMT: National technical regulation on Water Quality for irrigated agriculture
- QCVN 40: 2011/BTNMT: National Technical Regulation on Industrial Wastewater
- QCVN 02: 2009/BYT: National technical regulation on domestic water quality
Table 3.2: Table on the limits of water quality indicators
No Indicators Unit Limited Value
QCVN 38:2011/BTNMT: National technical regulation on Surface Water Quality for protection of aquatic lives
3 Total Suspended Solids (TSS) mg/L 100
4 Total Dissolved Solids (TDS) mg/L 1,000
QCVN 39:2011/BTNMT: National technical regulation on Water Quality for irrigated agriculture
3 Total Dissolve Solids (TDS) mg/L 2,000
QCVN 40: 2011/BTNMT: National Technical Regulation on Industrial Wastewater
- Column A presents the limit values regulation of pollution indicators for the discharge of industrial wastewater into water sources used for domestic water supply purposes
- Column B shows the limit values regulation of pollution indicators for the discharge of industrial wastewater into water sources not used for domestic water supply purposes
QCVN 02: 2009/BYT: National technical regulation on domestic water quality
RESULTS AND DISCUSSION
Research results on the status of Cau River water quality
Through 3 times of analyzing selected indicators during the period from July to October, the results are shown in Table 03:
Table 4.1: Analysis results of the determined indicators on Cau River water
COD (mg/L) Name Times Position
- In general, pH and temperature range between the limits for four types of standards
The analytical results indicate that the turbidity levels significantly exceed the standards set by 02:2009/BYT, rendering this water unsuitable for domestic use by local residents.
Figure 4.1: Analytical results of TSS
The analysis of suspended solids (TSS) indicates that positions 3 and 5 consistently meet the standard set by 38:2011/BTNM across all three samples In contrast, position 1 surpasses the permissible limit in all samples, while positions 2 and 4 exhibit values that fluctuate both above and below the limit.
Figure 4.2: Analytical results of TDS
1st time 2nd time 3rd time 38:2011/BTNMT
1st time 2nd time 3rd time 38:2011/BTNMT 39:2011/BTNMT
Figure 4.2, shows that each TDS value meets the standards 38:2011/BTNMT and
Figure 4.3: Analytical results of DO
For DO (figure 4.3), the analytical results at positions 1, 2, 3, and 5 in all of the three sample satisfy the standards of 38:2011/BTNMT and 39: 2011/BTNMT Only the value of
DO at position 4 is lower than these standards
Figure 4.4: Analytical result of BOD 5
The BOD5 measurements indicate that only the value at position 1 exceeds the National Technical Regulation on Industrial Wastewater Level A and Level B standards set by 40:2011/BTNMT Notably, the BOD5 value at position 1 is twice the acceptable limit for Level A, while the other positions remain within acceptable ranges.
1st time 2nd time 3rd time 38:2011/BTNMT 39:2011/BTNMT
1st time 2nd time 3rd time
Figure 4.5: Analytical results of COD
The analytical results for COD at all sampling sites exceed the standard of 40:2011/BTNMT Level A However, when evaluated against the 40:2011/BTNMT Level B standard, the findings show inconsistency across three sampling occasions, with some sites surpassing the limits during the initial sampling but falling below them in subsequent tests.
Impacts of socio- economic development activities on Cau River water quality
4.2.1 The situation of using Cau River water
The investigation results show that Cau river water in the study area is mainly used for agricultural production
Two pumping stations are designed to irrigate 128 hectares of paddy fields and 20 hectares of corn, beans, and peanuts The People's Committee of Tan Hung commune reports that approximately 190 cubic meters of water is pumped for agricultural use.
In various productive agricultural regions, water sources utilized do not originate from the Cau River For instance, in the Coc Luong, Cam Ha, and Hieu Chan dyke cultivation areas, local farmers rely on canals distant from the Cau River This choice is driven by the need for reliable water access and the desire to lower the costs associated with building and maintaining irrigation systems.
1st time 2nd time 3rd time 40:2011/BTNMT Level A 40:2011/BTNMT Level B
The thesis examined the utilization of Cau River water by local households, revealing that only 21 out of 60 residents directly use the river for activities such as cultivation and breeding, averaging about 210m³ per year This volume is minimal due to the river's deep water levels and steep banks, which complicate water extraction for agricultural purposes Additionally, the use of Cau River water for daily life has significantly declined, primarily attributed to severe water pollution concerns.
The traditional agricultural villages of Ngo Dao, Dao Thuong, Coc Luong, Hieu Chan, and Cam Ha have established a community group dedicated to collecting and disposing of waste in landfills Despite these efforts, challenges remain as garbage continues to be improperly discarded along the riverbanks.
Survey results indicate that households engaged in breeding activities lack sanitary manure pits, characterized by poorly organized heaps, inadequate covers, and absence of waterproof linings Furthermore, many households either do not have toilets or possess poorly constructed toilets that fail to mitigate unpleasant odors The livestock wastewater model is illustrated in the accompanying diagram (Figure 4.7).
The diagram illustrates that wash water and wastewater from barns are directly discharged into a pond and the Cau River, while a portion of the wastewater is utilized for garden irrigation Although this method offers economic benefits for farmers, it simultaneously contributes to water, air, and land pollution in nearby residential areas.
4.2.3 Types of socio- economic development activities a Agricultural activities
Survey findings indicate that the livelihoods in the villages are predominantly reliant on agricultural production The cultivation practices in the region can be categorized into two distinct areas: the inside area of the dike, which extends from the water's edge to the dike, and the outside area of the dike, characterized by alluvial land that is annually deposited and frequently altered by flooding and sand and gravel extraction activities.
- The amount of fertilizers used in agriculture
Garden Pond, Lake, Cau River…
Figure 4.7: Diagram of wastewater in breeding activity
An initial assessment of the effects of fertilizers on river water quality involved surveying fertilizer usage According to the 2013 Agricultural Report of Tan Hung Commune, the data on fertilizer application is detailed in Table 4.2.
Table 4.2: Amount of fertilizers used in the study area in 2013
Crops Area (ha) Weight of fertilizers (kg)
Manure Supe Phosphate Nitrogen Potash Lime powder Rice 1,154.720 12,219 6,283 2,792 2,094 4,462
[Source: Agricultural report of Tan Hung commune in 2013]
The data indicates that the application of Super Phosphate, totaling 25,604 kg, is 2.5 times greater than that of Nitrogen and four times higher than Potash in the study area This excessive use of fertilizers relative to the cultivated land area poses a risk of nutrient runoff, which can contaminate local waterways, including canals, streams, and the Cau River, ultimately degrading water quality.
Research indicates that trees absorb only one-third of the fertilizers applied, with the remaining two-thirds contaminating soil and surface water This runoff contributes significantly to pollution, adversely impacting the water quality of the Cau River.
- Types of waste from cultivating activities
Table 4.3: The impacts of waste on aquacultural and agricultural activities
Types of waste Pollutant Impacts
Solids in water Smell and components of garbage People, animals, river water environment…
Wastewater Concentration of toxins in water Ground and surface water, people, animals…
Fertilizers Component of fertilizer Soil, water…
Toxic substances in chemical plant protection
The impacts of cultivation activities are illustrated in Figures 4.4 and 4.5 In the first two samples, the BOD5 and COD values at position 3 met the standard levels However, the third sample showed elevated BOD5 and COD values exceeding the standard This increase is attributed to the dissolution and leaching of pollutants, such as fertilizers and chemical plant protection agents, from the dyke and soil into the Cau River during rainfall.
Research indicates that fresh manure from cattle and poultry is often not stored in sanitary pits, leading to a significant amount being washed into the Cau River and other water sources In the study area, approximately 4,474 buffaloes, cows, horses, and poultry are present, with about two-thirds grazing freely in fields and along embankments This uncontrolled grazing is a major contributor to the decline in water quality in the Cau River.
Table 4.4: The number of cattle and poultry in each village
Ngo Đao Buffaloes, cows, horses, ducks… 520 Đao Thuong Horses, chickens, pigs… 783
Coc Luong Buffaloes, horses, ducks… 934
Hieu Chan Cows, chickens, horses… 1,252
Cam Ha Ducks, buffaloes, pigs… 985
In Figure 4.3, position 4 shows the lowest dissolved oxygen (DO) levels and significantly higher chemical oxygen demand (COD) compared to other positions, likely due to nearby breeding activities The direct discharge of wastewater from unsanitary manure storage into the river is a primary factor contributing to the contamination of the water source.
The concentration of Chemical Oxygen Demand (COD) at position 4 is significantly elevated compared to other locations due to direct wastewater discharge from breeding activities into nearby rivers This pollution adversely affects water quality and poses a threat to aquatic organisms Additionally, sand and gravel extraction activities further contribute to the degradation of the aquatic environment.
(1) History of sand and gravel exploiting in the study area
Survey findings indicate that sand and gravel extraction activities began in 1995-1996, primarily driven by small-scale operations initiated by local households to meet construction needs in the area and nearby regions These activities were unregulated and lacked oversight from any governing bodies.
In 2000, the exploiting activities took place more boisterous This activity was only recognized when the local government sold the sandbanks to shipowners from other places
(2) The impact of exploiting activities on Cau River water quality
Solutions to improve Cau River water quality
Research has shown that human activities have significantly degraded the water quality of the Cau River To enhance the water quality in this region, the thesis presents several proposed solutions.
To optimize fertilizer use and prevent overapplication, it is essential to regulate the volume of fertilizers applied Emphasis should be placed on managing activities that produce fresh manure, such as livestock breeding Households are encouraged to construct proper toilets and manure pits that adhere to hygiene standards, ensuring they are enclosed and regularly cleaned to minimize odors Additionally, it is advisable to incubate fertilizers prior to application for enhanced effectiveness.
The use of chemical plant protection must adhere to the guidelines set by the Ministry of Agriculture and Rural Development, ensuring that applications are necessary and compliant with established standards This responsible approach minimizes adverse effects on humans, animals, and the environment After application, it is essential to properly dispose of packaging by either recycling or incinerating it to prevent pollution.
4.3.2 Socio-economic development solutions to improve Cau River water quality
Socio-economic development plays a crucial role in enhancing the quality of life and fostering sustainable growth It is vital to address environmental concerns, particularly those related to the Cau River, in the context of this development Integrating socio-economic progress with environmental protection is essential for achieving comprehensive and sustainable development in the region and within specific research studies Therefore, socio-economic strategies must be prioritized in any project aimed at environmental conservation.
The study area relies heavily on agriculture, characterized by low population density and high poverty rates, highlighting the urgent need for financial support to foster industrial development and infrastructure To enhance waste management, significant capital investment and technical advancements are essential, particularly in establishing large-scale sewage treatment systems for livestock households, which can demonstrate the effectiveness of waste treatment models.
Increase the knowledge and awareness of people
The study highlights a significant lack of awareness regarding environmental issues in the area, where outdated customs lead to indiscriminate garbage disposal around residential zones and the Cau River Excessive use of fertilizers and plant protection chemicals further exacerbates the problem To address these challenges, it is crucial to enhance public education and raise awareness about environmental protection, focusing on sustainable practices and responsible waste management.
+ Organizing the contents to research about knowledge of environmental protection and Cau River water quality, works to avoid the coastal erosion, for governmental agencies and community
+ Providing some educational contents about the awareness of environmental protection in schools and extracurricular meetings in villages
To successfully implement afforestation projects and develop livestock waste treatment systems, it is essential to enhance the technologies and techniques for designing and constructing effective forest growth and agroforestry methods.
Increase the managing capacity for local authorities
Local authorities possess a deep understanding of their communities, yet management in the study area faces challenges due to the limited capacity of certain officials To address this issue, it is essential to prioritize training and development in leadership, expertise, and scientific knowledge for these cadres Additionally, organizing extracurricular meetings at the local level with the involvement of experts and environmental organizations can further enhance community management efforts.
The policies are to open the way for the project, the model is implemented smoothly, in addition it helps to contribute, promote and replicate of the project
- The planning policies of using the cultivation land along the river, particularly forest land
- Preferential policies for organizations and households which actively participate in the environmental protection and development of forests
- Policies to increases financial and technical to the infrastructural construction to protect the dike and river bank
- Policies on environmental management and forest management
This thesis examines the effects of socio-economic development activities on the water quality of the Cau River in five villages of Tan Hung commune However, there is a need for broader research that encompasses a more comprehensive analysis of the entire riparian zones along the Cau River.
- Need to have the solutions to reduce the environmental pollution as well as pollutions of Cau River water environment
Managers must enhance awareness campaigns to educate individuals and businesses about the importance of protecting and using water resources wisely Additionally, implementing penalties for those who engage in activities that pollute water sources is essential for safeguarding this vital resource.
CONCLUSIONS
Based on the research results, the thesis gives some conclusions as follows:
The analysis of Cau River water quality revealed significant findings regarding various indicators Turbidity levels were found to be substantially higher than the standard 02:2009/BYT While pH and Total Dissolved Solids (TDS) remained within permissible limits, Total Suspended Solids (TSS) exceeded the standard 38:2011/BTNMT at positions 1, 2, and 4, with positions 3 and 5 meeting the criteria Dissolved Oxygen (DO) levels were generally compliant, except for position 4, which surpassed the standards set by 38:2011/BTNMT and 39:2011/BTNMT Additionally, Biochemical Oxygen Demand (BOD5) at position 1 exceeded the standard 40:2011/BTNMT, and Chemical Oxygen Demand (COD) concentrations were higher than the standard 40:2011/BTNMT Level A across all positions.
The Cau River's water usage for daily life in the study area is minimal, highlighting the need for increased environmental awareness among local residents Despite this, some villages, such as Cam Ha and Hieu Chan, continue to dispose of waste along the dyke, emphasizing the ongoing challenge of waste management in the region.
The excessive use of fertilizers and plant protection chemicals continues to lead to soil contamination, resulting in runoff into lakes and the Cau River Additionally, the improper disposal of fresh manure from breeding activities exacerbates environmental issues While community awareness of environmental protection has improved, garbage management remains a significant source of pollution in the commune.
4 Thesis has proposed some technical, economic and social solutions in order to improve Cau River water quality and the environmental protection of commnue.