Variability of soil chemistry following irrigation with recycled municipal effluent: a Great Western vineyard case study

In areas of Australia where viticultural operations have been limited by lack of an acceptable irrigation water source, considerable expansion has occurred through the use of recycled wastewater. Despite this rapid expansion, little is known of the potential impacts of the water’s chemical constituents on soil properties, or the long-term sustainability of the vineyards using the water. In order to establish the impacts of drip irrigated recycled wastewater on a vineyard in Great Western, Australia, a study comparing the soils from the vineyard inter-row and row area was undertaken. Chemical and physical properties of the soil with varying distances from the drip emitter were also investigated. During the irrigation season, significant differences between the inter-row and row area were found for several chemical parameters including pH(1:5soil/water) (P<0.001), electrical conductivity (EC1:5) (P<0.001), water-soluble sodium (WS Na+) (P<0.001), and water-soluble chloride (WS Cl-) (P<0.001). This paper will discuss differences observed between soil properties of the inter-row and vine row area, as well as the spatial distribution of solutes under the drip emitter.

Drip irrigation of treated municipal effluent in vineyards

Vine-row soil chemical and physical properties were significantly and detrimentally altered by drip irrigation of treated municipal effluent. Hydraulic gradients under the drip-emitter fostered strong chemical gradients and high variability of vine-row soil parameters, complicating soil management. Gypsum improves soil properties without impacting vine production when applied in small quantities.

The four national taps of Singapore: a holistic approach to water resources management from drainage to drinking water

 Water resources in Singapore are managed following the principles of a closed loop hydrologic cycle by one agency, the Public Utility Board (PUB), which promotes its management philosophy through the Four National Taps of Singapore program. The four national taps are: water from local catchment areas; imported water (from Malaysia); reused water (known as NEWater); and desalinated water. Given the uncertainty of water imports, the remaining three national taps have become increasingly important and this paper begins with a general overview of the innovative programs implemented by PUB in support of these three taps. Stormwater runoff is captured from two-thirds of Singapore’s land area and stored in reservoirs for subsequent use. Stormwater management is an important component of the catchment area tap and extensive low impact development (LID) implementation has become a priority through the ABC (Active, Beautiful, Clean) Waters Program. Examples of several ABC Waters projects are discussed. NEWater currently supplies 30% of the country’s demand and this is projected to increase to 50% by 2060. NEWater plants take treated wastewater through the additional steps of microfiltration, reverse osmosis and ultraviolet treatment for use primarily in industry, although a portion also is blended into the municipal reservoirs. Singapore’s single desalination plant currently meets 10% of its demand, with a second plant to be completed in 2013 that will more than double production. Also discussed are the results of recently completed pilot projects related to stormwater management including testing of E. coli in runoff from high density residential areas, a blind taste test and survey on acceptance of NEWater, and a survey of Singaporean understanding about stormwater management issues.Water resources in Singapore are managed following the principles of a closed loop hydrologic cycle by one agency, the Public Utility Board (PUB), which promotes its management philosophy through the Four National Taps of Singapore program. The four national taps are: water from local catchment areas; imported water (from Malaysia); reused water (known as NEWater); and desalinated water. Given the uncertainty of water imports, the remaining three national taps have become increasingly important and this paper begins with a general overview of the innovative programs implemented by PUB in support of these three taps. Stormwater runoff is captured from two-thirds of Singapore’s land area and stored in reservoirs for subsequent use. Stormwater management is an important component of the catchment area tap and extensive low impact development (LID) implementation has become a priority through the ABC (Active, Beautiful, Clean) Waters Program. Examples of several ABC Waters projects are discussed. NEWater currently supplies 30% of the country’s demand and this is projected to increase to 50% by 2060. NEWater plants take treated wastewater through the additional steps of microfiltration, reverse osmosis and ultraviolet treatment for use primarily in industry, although a portion also is blended into the municipal reservoirs. Singapore’s single desalination plant currently meets 10% of its demand, with a second plant to be completed in 2013 that will more than double production. Also discussed are the results of recently completed pilot projects related to stormwater management including testing of E. coli in runoff from high density residential areas, a blind taste test and survey on acceptance of NEWater, and a survey of Singaporean understanding about stormwater management issues.