In spite of modern technological advancements that can convert wastewater into potable water, the acceptability of recycled water is generally low. This study examined strategies for increasing the public acceptability of recycled water. Based on the elaboration likelihood model, I hypothesized that issue relevance, argument quality, and delivery type would interact to produce differing levels of support for potable recycled water. Undergraduate students took part in a 2 (issue relevance: low, high) x 2 (argument quality: weak, strong) x 2 (delivery: textual, pictorial) online study relating to their opinion and support for the potential implementation of a potable recycled water system on campus. Issue relevance was manipulated by varying the completion date of implementing the system (low: five years; high: one year). Argument quality was manipulated by varying the complexity of the message presented (weak: point-form; strong: paragraph form). Delivery was manipulated by presenting water recycling processes in a textual or pictorial format. The hypotheses were not supported, although the means were in the predicted direction. Limitations and future directions are discussed. / Graduate

This paper identifies factors that are associated with higher levels of public acceptance for recycled and desalinated water. For the first time, a wide range of hypothesized factors, both of socio-demographic and psychographic nature, are included simultaneously. The key results, based on a survey study of about 3000 respondents are that: (1) drivers of the stated likelihood of using desalinated water differ somewhat from drivers of the stated likelihood of using recycled water; (2) positive perceptions of, and knowledge about, the respective water source are key drivers for the stated likelihood of usage; and (3) awareness of water scarcity, as well as prior experience with using water from alternative sources, increases the stated likelihood of use. Practical recommendations for public policy makers, such as key messages to be communicated to the public, are derived. (authors' abstract)

Agricultural production in Monterey County, California is a multi-billion dollar industry. Near the coast, seawater intrusion has threatened to degrade the groundwater quality due to over-pumping of the aquifer. The Monterey Regional Water Pollution Control Agency (MRWPCA), in partnership with the Monterey County Water Resources Agency, has provided recycled water since 1998 to over 12,000 acres of prime agricultural farmland in the northern Salinas Valley in an effort to reduce groundwater removal. The dominant soil types in the region are clay loam and clay soils, which are both susceptible to sodium (Na) accumulation and water infiltration problems. Recycled water blended with well water is used to irrigate cool season vegetables (i.e., artichokes, broccoli, Brussels sprouts, celery, cauliflower, and lettuce) and strawberries. A long-term study was implemented by MRWPCA to monitor salinity levels in commercial vegetable fields because of grower concerns that salts in the recycled water would have long term effects on soil quality. Accumulation of salts over time would make the soil less productive. Soil salinity levels were monitored at three Control and three Test Sites beginning in the spring of 2000. The Control Sites received well water, and the adjacent Test Sites received an approximate 2:1 blend of recycled and well water, respectively. Control and Test Sites were paired based on location to compare the same soil, crop, drainage systems, and farming practices. The soil was sampled three times per year from all sites: spring (before planting), mid-summer after harvest of the first crop, and late fall after the second crop harvest. Composites of four cores were collected at each site from the zero to 36-inch depth at 12-inch intervals. Each 12-inch interval soil sample was analyzed for pH, electrical conductivity (ECe), extractable cations (Na+, Ca2+, Mg2+, and K+) and extractable anions (Cl-, NO3-, and SO4-). After 10 years of monitoring, the data showed that using recycled water blended with well water at the Test Sites increased the ECe of the soil profile from 2.1 to 2.5 dS/m and increased the sodium adsorption ratio (SAR) from 3.0 to 3.9. The data also showed that using well water at the Control Sites increased the ECe of the soil profile from 1.4 to 2.6 dS/m and the change in SAR was negligible. The Test and Control Sites were significantly different for ECe and SAR, which was expected considering a higher salt content in the recycled water compared to the well water. The significant differences for ECe and SAR were associated with the significant differences in soil Na+ levels between the Test and Control Sites. The SAR and ECe of soil samples from all sites were in a range acceptable for vegetable production. The use of recycled water for irrigation of cool season vegetables and strawberries in the study area has not shown an indication of degraded soil productivity. Based on vegetable production and the slow increase of salts in the soil, recycled water can be used for long-term irrigation with proper management.

7 pp. / Agriculture is by far the largest water-demanding sector in Arizona, accounting for 70% of water demand (ADWR, 2009). Arizona’s agriculture industry is extremely diversified, producing many crops that can legally be irrigated with recycled water, including cotton, alfalfa, wheat, citrus, and vegetables. Throughout the State, farming communities are taking advantage of increasing supplies of recycled water.

In response to water supply depletion challenges, countries such as Australia, the United States, and Namibia have implemented technologies that treat wastewater up to the standards permissible to use for irrigation, toilet flushing, and even drinking water. However, many of these countries have been unable to successfully implement some of their ambitious reclaimed water reuse projects due to negative public perceptions of recycling wastewater. The focus of this study was to understand which factors in risk perception theory are the most influential in shaping community perceptions of reclaimed water reuse as a future source of drinking water within Hillsborough County. The research design was comprised of a mixed methodology approach (quantitative and qualitative analyses). The methods for assessing how each of the five main factors played a role in shaping risk perception in each of the communities was comprised of three main analyses, including spatial, statistical (through multiple regression modelling in R), and personal interview data (an HOA leader, one key informant, and a focus group). Residents (n=417) from various neighborhoods were interviewed through surveys which will evaluate factors found in literature that have been shown to have the most effect in shaping risk perception theory.

Given the important role that trust plays in acceptance of water management schemes, the current research investigated the characteristics and determinants of trust by developing a social-psychological model of trust in the area of water management and reuse. The research advanced a theoretical understanding of trust by using social identity theory and the relational model of trust as a framework and providing a systematic examination of the relationships between the variables in the hypothesised trust model. The proposed trust model was tested across three potentially different perceived risk contexts; low, medium and high. Analysis through path modelling provided strong support for the hypothesised model. In all three contexts trust in the water authority was a significant predictor of acceptance of the water management scheme, and risk perceptions mediated the relationship between trust and acceptance. In other words higher levels of trust in the authority were associated with lower perceptions of risk, which were in turn associated with higher levels of acceptance. In Study 4, which was set in the high perceived risk context of the proposed indirect potable reuse scheme in Toowoomba, perceptions of risk had the strongest direct effect on acceptance of the scheme, and the trust, risk and acceptance relationship was stronger than it was in the other studies. The relational variables of procedural fairness, identification with one’s community, ingroup membership of the water authority and a social bond (shared values) with the water authority were all found to impact on trust, either directly or indirectly. In addition, the instrumental variable of the credibility of the authority (measured as technical competence and a lack of vested interests) was found to have a significant impact on trust. Taken together, the results provide support for social identity theory and the relational model of trust as a framework for understanding trust in authorities. The results are also consistent with literature that suggests that the relational and instrumental models of trust are not incompatible (e.g., Edwards & Kidd, 2003; Tyler & Kramer, 1996). The findings from this research program clearly have a practical application for improving acceptance of water management schemes. The combined results demonstrate the importance of trust in the water authority in reducing perceived risk and thus increasing acceptance of schemes. The results highlight the need for water authorities and policy makers to build public trust through procedural fairness, building a sense of the water authority as a member of the community, and through demonstrating technical competence and concern for the interests of the public.

Given the important role that trust plays in acceptance of water management schemes, the current research investigated the characteristics and determinants of trust by developing a social-psychological model of trust in the area of water management and reuse. The research advanced a theoretical understanding of trust by using social identity theory and the relational model of trust as a framework and providing a systematic examination of the relationships between the variables in the hypothesised trust model. The proposed trust model was tested across three potentially different perceived risk contexts; low, medium and high. Analysis through path modelling provided strong support for the hypothesised model. In all three contexts trust in the water authority was a significant predictor of acceptance of the water management scheme, and risk perceptions mediated the relationship between trust and acceptance. In other words higher levels of trust in the authority were associated with lower perceptions of risk, which were in turn associated with higher levels of acceptance. In Study 4, which was set in the high perceived risk context of the proposed indirect potable reuse scheme in Toowoomba, perceptions of risk had the strongest direct effect on acceptance of the scheme, and the trust, risk and acceptance relationship was stronger than it was in the other studies. The relational variables of procedural fairness, identification with one’s community, ingroup membership of the water authority and a social bond (shared values) with the water authority were all found to impact on trust, either directly or indirectly. In addition, the instrumental variable of the credibility of the authority (measured as technical competence and a lack of vested interests) was found to have a significant impact on trust. Taken together, the results provide support for social identity theory and the relational model of trust as a framework for understanding trust in authorities. The results are also consistent with literature that suggests that the relational and instrumental models of trust are not incompatible (e.g., Edwards & Kidd, 2003; Tyler & Kramer, 1996). The findings from this research program clearly have a practical application for improving acceptance of water management schemes. The combined results demonstrate the importance of trust in the water authority in reducing perceived risk and thus increasing acceptance of schemes. The results highlight the need for water authorities and policy makers to build public trust through procedural fairness, building a sense of the water authority as a member of the community, and through demonstrating technical competence and concern for the interests of the public.

Given the important role that trust plays in acceptance of water management schemes, the current research investigated the characteristics and determinants of trust by developing a social-psychological model of trust in the area of water management and reuse. The research advanced a theoretical understanding of trust by using social identity theory and the relational model of trust as a framework and providing a systematic examination of the relationships between the variables in the hypothesised trust model. The proposed trust model was tested across three potentially different perceived risk contexts; low, medium and high. Analysis through path modelling provided strong support for the hypothesised model. In all three contexts trust in the water authority was a significant predictor of acceptance of the water management scheme, and risk perceptions mediated the relationship between trust and acceptance. In other words higher levels of trust in the authority were associated with lower perceptions of risk, which were in turn associated with higher levels of acceptance. In Study 4, which was set in the high perceived risk context of the proposed indirect potable reuse scheme in Toowoomba, perceptions of risk had the strongest direct effect on acceptance of the scheme, and the trust, risk and acceptance relationship was stronger than it was in the other studies. The relational variables of procedural fairness, identification with one’s community, ingroup membership of the water authority and a social bond (shared values) with the water authority were all found to impact on trust, either directly or indirectly. In addition, the instrumental variable of the credibility of the authority (measured as technical competence and a lack of vested interests) was found to have a significant impact on trust. Taken together, the results provide support for social identity theory and the relational model of trust as a framework for understanding trust in authorities. The results are also consistent with literature that suggests that the relational and instrumental models of trust are not incompatible (e.g., Edwards & Kidd, 2003; Tyler & Kramer, 1996). The findings from this research program clearly have a practical application for improving acceptance of water management schemes. The combined results demonstrate the importance of trust in the water authority in reducing perceived risk and thus increasing acceptance of schemes. The results highlight the need for water authorities and policy makers to build public trust through procedural fairness, building a sense of the water authority as a member of the community, and through demonstrating technical competence and concern for the interests of the public.

Water shortages resulting from increased demand or reduced supply may be addressed, in part, by redirecting recycled water for irrigation, industrial reuse, groundwater recharge, and as effluent discharge returned to streams. Recycled water is an essential component of integrated water management and broader adoption of recycled water will increase water conservation in water-stressed coastal communities. This study examined spatial patterns of recycled water use in Florida in 2009 and 2015 to detect gaps in distribution, quantify temporal change, and identify potential areas for expansion. Databases of recycled water products and distribution centers for Florida in 2009 and 2015 were developed by combining the 2008 and 2012 Clean Water Needs Survey databases with Florida’s 2009 and 2015 Reuse Inventory databases, respectively. Florida increased recycled water production from 674.85 mgd in 2009 to 738.15 mgd in 2015, an increase of 63.30 mgd. The increase was primarily allocated to use in public access areas, groundwater recharge, and industrial reuse, all within the South Florida Water Management District (WMD). In particular, Miami was identified in 2009 as an area of opportunity for recycled water development, and by 2015 it had increased production and reduced the production gap. Overall, South Florida WMD had the largest increase in production of 44.38 mgd (69%), while Southwest Florida WMD decreased production of recycled water by 1.68 mgd, or 3%. Overall increase in use of recycled water may be related to higher demand due to increased population coupled with public programs and policy changes that promote recycled water use at both the municipal and individual level.

ABSTRACT EFFECTS OF RECYCLED WATER ON LANDSCAPE PLANTS Casey Ray Miranda Recycled water is water that has been previously used, has suffered a loss of quality, and has been properly treated for redistribution (Wu et al. 2001). The use of recycled water as an alternative to fresh water in the landscape can have positive and negative effects. Experimentation on 40 different plant species during a 32 week period (2 phases of 16 weeks), was conducted to analyze the effects of recycled water irrigation on the appearance of landscape plants. Each species of plant was planted into 10 individual number 2 pots and irrigated with recycled water daily. Media and water were tested for nutrients and other constituents. In phase I there were four different species of grasses and grass-like plants, five different perennials, five species of shrubs, and four annuals tested; while phase II tested four species of herbaceous perennials, eight different species of shrubs, six species of groundcovers, and four species of annuals. All tests were conducted at the Paso Robles Waste Water Treatment Plant. Of the grasses and grass like species Yucca spp. and Buchloe spp. performed best. Osteospermum fruticosum, Lavandula angustifolia, Rosmarinus officinalis, Phormium tenax, and Pennisetum setaceum had the best appearance of the herbaceous perennials tested. For the shrubs, Coprosma repens, Cistus purpureus, Dodonea viscosa, Eleagnus pungens, Baccharis pilularis, Ceanothus thysiflorus, Thuja orientalis, and Nerium oleander had the best appearance when irrigated with recycled water. The best annuals were Senecio cineraria, Antirrhinum majus, Primula spp., Viola spp., and Calendula officinalis. Of the groundcovers Heuchera spp., Lonicera japonica, Vinca major, Hedera helix, and Ceanothus griseus had the best results. From the experiment a list of tolerant and non-tolerant plants was compiled (Appendices 1 and 2). While many plants were capable of developing and growing normally, other plants were sensitive to recycled water irrigation. In order to prevent salt damage to plants and expand the use of recycled water, salt tolerance of landscape plant material must be identified (Niu et.al, 2006).