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    Pollution of the aquatic biosphere by arsenic and other elements in the Taupo volcanic zone : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biology at Massey University
    (Massey University, 1994) Robinson, Brett Harvey
    An introduction to the Taupo Volcanic Zone and probable sources of polluting elements entering the aquatic environment is followed by a description of collection and treatment of samples used in this study. The construction of a hydride generation apparatus for use with an atomic absorption spectrophotometer for the determination of arsenic and other hydride forming elements is described. Flame emission, flame atomic absorption and inductively coupled plasma emission spectroscopy (I.C.P.-E.S.) were used for the determination of other elements. Determinations of arsenic and other elements were made on some geothermal waters of the area. It was found that these waters contribute large (relative to background levels) amounts of arsenic, boron and alkali metals to the aquatic environment. Some terrestrial vegetation surrounding hot pools at Lake Rotokawa and the Champagne Pool at Waiotapu was found to have high arsenic concentrations. Arsenic determinations made on the waters of the Waikato River and some lakes of the Taupo Volcanic Zone revealed that water from the Waikato River between Lake Aratiatia and Whakamaru as well as Lakes Rotokawa, Rotomahana and Rotoehu was above the World Health Organisation limit for arsenic in drinking water (0.05 µg/mL) at the time of sampling. Arsenic accumulates in the sediments of the Waikato River and Lakes of the Taupo Volcanic Zone. The levels were variable, but characteristically around 100 µg/g. Trout taken from the Waikato River and some lakes in the Taupo Volcanic Zone, had flesh arsenic concentrations of the same order of magnitude as the water from which they were taken. Trout from Lakes Rotorua, Rotoiti and Rotomahana contained average flesh mercury concentrations above the World Health Organisations limit for mercury in foodstuffs (0.5 µg/g). There were positive correlations between weight, length and flesh mercury concentration. Freshwater mussels from Lakes Rotorua and Tarawera had arsenic concentrations above the World Health Organisations limit for arsenic in foodstuffs (2 µg/g). Shellfish taken from the mouth of the Waikato river and from Raglan were below the World Health Organisation's limit for arsenic and mercury. Aquatic macrophytes from the Waikato River had arsenic concentrations many times greater than the water from which they were taken. Some samples of Ceratophyllum demersum had arsenic concentrations above 1000 µg/g dry weight. Water cress from the Waikato River at Broadlands and Orakei Korako contained on average 400 µg/g and 30 µg/g arsenic respectively. An experiment was conducted on the uptake of arsenic by water cress. It was found that water cress does accumulate arsenic if placed in an arsenic solution.
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    The impact of the closure and decommissioning of the Wainuiomata Waste Water Treatment Plant on the water quality of the Wainuiomata River : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Water Quality at Massey University
    (Massey University, 2004) De Silva, Josephine
    The quality of the Wainuiomata River (particularly downstream of the Wainuiomata Waste Water Treatment Plant) has been affected over the years (e.g. eutrophication) by a number of contaminants, such as nutrients and faecal bacteria. The main source of these contaminants has been the treated effluent discharged into the river from the Wainuiomata Waste Water Treatment Plant (WWTP). The WWTP has been discharging treated effluent into the river since the 1950's. This sewage treatment plant was decommissioned in November 2001 and is now used solely as a pumping station. Sewage from Wainuiomata is now piped over to the new sewage treatment plant in Seaview. This research project aimed to examine the impact of the WWTP closure on the water quality of the Wainuiomata River. Water samples were collected from a number of selected sites over a period of three months: January 2003 to March 2003, above and below the WWTP site. For this particular study, the microbiological, chemical (nutrients) and biological parameters were assessed as follows: Escherichia coli and total coliforms (microbiological) dissolved reactive phosphorus (DRP), nitrate nitrogen and ammoniacal nitrogen (chemical) and periphyton (biological) for biomass and taxa identification. The results for each of the above parameters sites were compared with historical data obtained from Greater Wellington Regional Council (2003). Overall this research has shown that the closure of the WWTP has impacted on the J5 site (Golf Course), which is downstream of the WWTP, in a number of ways. The chemical indicator levels (NO3-N, NH4-N and DRP) have dropped significantly; periphyton was still in abundance at site J5 (no real improvement seen) and the median level of the microbiological indicator, E.coli has reduced. However, site J5 on a number of occasions, did not comply with the Microbiological Water Quality Guidelines for Marine and Freshwater Recreational Areas (2003). Sites sampled upstream of the WWTP, particularly the tributary sites (Black Creek and Wainuiomata Stream), also did not comply with the guidelines on a number of occasions. This is a concern, as the public are known to swim near where these tributaries enter the Wainuiomata River. The effects of storm water or land runoff may have affected the results on two occasions (when there had been rainfall) however, on all other occasions where high E.coli levels were observed, the effects of storm water and runoff would have been minimal, as there had been very little rain. The Wainuiomata River is used for recreational activities such as swimming, canoeing and fishing; therefore an important resource. Any water quality concerns (namely, E.coli levels and periphyton proliferation), therefore need to be monitored by the Greater Wellington Regional Council and actions taken to eliminate these concerns.
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    Integrated water quality management in Thailand : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Resource and Environmental Planning, Massey University,
    (Massey University, 1995) Siriwan, Chandanachulaka
    This thesis analyses the theoretical requirements for an integrated approach to freshwater resource management. The New Zealand and the Thai systems are then compared to understand •variations between the two systems of planning at three different stages - Pre-Implementation, Implementation and Post-Implementation Stages. Finally, recommendations are made for improving the Thai system. The research findings confirm that the New Zealand system measures up to criteria for ensuring sustainable development of freshwater resources. The system provides for planning based on river catchments and a variety of policy instruments may be used to achieve country objectives at all levels in the system. The Thai system provides for planning and developing of policy at national level and some parts of decision-making are delegated to the provincial level. At the implementation stage, the New Zealand system provides for a non-regulatory approach. Whereas, in Thailand, methods of policy implementation based on regulatory approach, are well-developed. At Post­ Implementation stage, the New Zealand system provides for a monitoring system and less severe penalties than Thailand, where the system does not explicitly provide for monitoring, but severe penalties are imposed for deliberate actions to pollute rivers. The findings suggest that the Thai system of water resources management can be improved in a number of ways, but the fragmentation of the planning process is the principle obstacle. Besides that, various future research areas identify which improvements to river water quality management in Thailand are a priority.
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    Factors affecting phosphate concentrations in surface and subsurface runoff from steep East Coast hill country : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Applied Science, Department of Soil Science, Massey University
    (Massey University, 1998) Blennerhassett, Jamie D
    Eutrophication is a problem receiving much attention within New Zealand and throughout the rest of the world. Problems associated with eutrophication cause major financial, aesthetic and recreational costs to not only commercial and recreational water users but to society in general. The major nutrient of concern in relation to eutrophication is phosphorus (P) as it is often considered to be the limiting factor. The two major areas from which P enters waterways are point sources and non-point sources. Point sources are relatively easy to identify and quantify. Non-point sources however, are less easy to quantify due to the size of areas from which P is sourced and the number of varying factors which can affect the amount of P which is lost to water-ways. This study investigated P concentrations in surface runoff and subsurface flow from steep east coast hill country. Factors studied included aspect, soil P status, season and fertiliser addition. The study was carried out on grazed pasture farmlets, in which there were 'High P' and 'Low P' fertiliser regimes. Each regime had north and south facing aspects. Four sites were used in the study. High P North (HPN), High P South (HPS), Low P North (LPN) and Low P South (LPS). Simulated rainfall was applied to the sites and surface runoff samples were collected and analysed for dissolved reactive phosphate concentration (DRP). Superphosphate fertiliser was then applied at 20 kg P ha-1 to each site and the runoff procedure was repeated 7 weeks and 14 weeks the lower P soil test values on the south-facing slopes. A water extractable P test provided a better correlation with runoff DRP concentrations for individual runoff events than the Olsen P test. Both tests however, provided poor correlations when all of the Runs were combined. This was due largely to the large increase in DRP concentrations in surface runoff in Run 3 with no corresponding increase in soil tests. There was no apparent relationship between fertiliser regime i.e. soil P status, and the concentration of DRP in subsurface runoff. In Run 3 however, there was a marked increase in subsurface DRP concentration for both sites which was consistent with the surface runoff results and supported the theory of soil moisture playing a major role in determining the DRP concentration in water. The study suggests that the greatest risk of P loss from soil to surface waters will be from northerly aspects with high fertiliser histories during the summer months when soil moisture levels are low.
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    The effects of tillage practices and cropping pattern on nonpoint source pollution and soil quality : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Agricultural Engineering at Massey University
    (Massey University, 1997) Guo, Peng
    Soil erosion is one of the most serious environmental problems facing world agriculture. In New Zealand, with the current low financial returns from pastoral-based farming, land which was previously unaffected by soil erosion is being intensively farmed and therefore becoming more susceptible to soil erosion and nonpoint source pollution. Adoption of soil resource management and agricultural practices that seek to conserve soil and water resources and minimise environmental degradation is attracting overwhelming interest among scientists and general public. Therefore, the main objective of this study was to assess the effects of selected tillage practices on soil physical properties, soil and water runoff, and water quality under selected cropping pattern. Experiments were conducted on a Ohakea silt loam comparing crop production (barley and oats double crop rotation) using conventional tillage (MP), no-tillage (NT), and pasture (P) (as a control treatment) and assess their impact on erosion and selected soil properties. It was expected that this relatively heavy soil type would be sensitive to cultivation management systems and was therefore suitable for a comparison of tillage methods. The treatments were arranged in a randomised complete block (RCB) design with four blocks of three treatments. In the field experiment, soil bulk density, water content, infiltrability, penetration resistance and earthworm populations were measured during two cropping seasons after barley and oats crops harvest in March and August 1996 respectively. Generally, these soil properties were significantly (P≤ 0.05) affected by tillage practices. Soil water content, infiltrability, and earthworm populations were similar in the NT and P treatments, but significantly higher than those found in the MP treatment. Conversely, soil bulk density at 0 - 50 mm depth was in the order of MP > NT > P. In the laboratory experiment, soil and water runoff, leachate volume, pH and nutrient losses from soil erosion were measured under a rainfall simulator. "Rainfall" intensity used was at an average application rate of 50 mm/hr for one hour, simulating a rainstorm. Mean data from the two experiments suggested that the surface water runoff and soil sediment in runoff were higher in the MP treatment than in the NT and P treatments, and were in the order of MP > NT = P and in a ratio of 4:1:1 and 30:1:1 respectively. Conversely, the volumes of water leachate were higher for the NT and P treatments than for the MP treatment, and in a ratio of 4:1:1 respectively. Soil pH from both water runoff and leachate was at an average of 7.4 and 7.2 respectively, but not different among the three treatments. Nutrient losses in surface water runoff were found to be significantly higher (P≤ 0.05) in the MP treatment (N=1.45 mg/m2, P=1.02 mg/m2, and K=8.3 mg/m2) than those with the NT (N=0.76 mg/m2, P=0.65 mg/m2, and K=6.8 mg/m2). Nutrient losses from NT and pasture treatments were similar. One year's data including two cropping seasons indicate that conventional tillage practices can result in high surface runoff and sediment loss and adversely affect runoff water quality. Such tillage practices are likely to lead to unsustainable land resource management and decreasing crop yields. On the other hand, conservation tillage practices such as no-tillage and continuous pasture cover reduced soil and water erosion, improved soil physical properties and runoff water quality, and conserved land resources leading to enhanced land productivity and agricultural sustainability.