Michele+Alshouli+Final+Project

=**Developing a monitoring program for the detection of Carbamazepine, Triclocarban, and Triclosan as wastewater tracers to assess wastewater effluent discharge contribution to source water in the Philadelphia waterway.**=

By: Michele Alshouli
__Abstract__ Due to the realization that waterborne diseases lead to production of microorganism, ideas soon emerged to use microorganisms as indicators to trace the source of wastewater intrusion. Tracers now are being used more frequently as a precaution for invasive treated effluents unintentionally contaminating source water (Gasser et al. 398-404). Using a monitoring study with microorganisms as wastewater indicators, it has been shown that Philadelphia’s watershed can have up to 40-70% treated wastewater during a drought as well as untreated wastewater input from sanitary sewer or combined sewer overflows during floods. It is of increasing importance for drinking water supplies to better understand and assess the contribution of treated wastewater effluent to the waterways.

__Introduction__ Pharmaceutical and personal care products (PPCPs) are widely used and abundant in the wastewater system. PPCPs were first detected in clean natural bodies of water and treated wastewater in late 1990’s; since then, many methods have been developed for their detection with the consensus that the primary source of PPCPs is through sewage treatment plant discharges and combined sewer overflows (CSO) (Ort et al. 6024-6035). Since PPCPs are mostly polar and potentially resistant to biotransformation, some are not degraded or removed during wastewater treatment; thus, pharmaceuticals may reach soils by effluent discharge or sludge use, where there is a potential for bioconcentration (Thompson et al. 63-67). PPCPs are ideal for utilization as tracers to assess wastewater discharge due to their biorefractoryness and abundance. The stability and abundance of Carbamzepine (CBZ), Triclocarban (TCB), and Triclosan (TCS), allow for their application as tracers.

Of the many pharmaceutical compounds analyzed, one of the most frequently detected compounds is CBZ, which has over the last few decades been continuously supplied to and released from WWTPs (Arye, Dror and Berkowitz 244-252). CBZ is a common drug prescribed in high dosages (100-200 mg daily) for patients with severe pain syndromes associated with neurological disorders and is used for its antiepileptic and psychotropic activity. CBZ is a polar pharmaceutical and lacks sites for specific interactions with soils and sediments, giving nonappreciable sorption properties and shows no elimination during wastewater treatment (Kosjek et al. 6256-6261). TCB and TCS are antimicrobials currently added to a large number of consumer products, such as household soaps and detergents (Cha and Cupples 2522-2530).

__Stability Studies__ Kosjek et all show CBZ is stable and the most effective removal techniques for CBZ are ozonation, UV/H2O2, or photolytic degradation with TiO21, which is not applied at the NE WWTP.(Kosjek et al. 6256-6261) Ying et al indicate that TCB or TCS do not degrade fast with its primary biodegradation half-life of weeks and ultimate biodegradation half-life of months. Laboratory experiments showed that TCB and TCS were degraded in the aerobic soil with half-life of 108 days and 18 days, respectively (Ying, Yu and Kookana 300-305). The combined predicted no effect concentration for drinking water and fish consumption for CBZ is 226,000 ng/L in North America and Europe. Measured environmental concentrations ranged from 150 to 220 ng/L, indicating that CBZ and its major metabolites should have no appreciable risk to human health through environmental exposures based on available human data (Cunningham et al. 343-351)(Cunningham et al. 343-351). So CBZ will be used solely as a tracer, though the detectable levels are not a concern yet. However, in a retail survey Triclocarban (TCB) and Triclosan (TCS) were found in 76% of liquid soaps and 29% of bar soaps (Perencevich, Wong and Harris 281-283). Such release of TCB and TCS has the potential to cause a number of environmental and human health problems, including: the bioaccumulation of TCB, TCS and methyltriclosan (a lipophilic metabolite of TCS). TCB has shown to be toxic and cause disruption to the endocrine system (Tizaoui, Grima and Hilal 637-643). TCB and TCS are not only suitable for tracers, but their detection and monitoring will be used to quantify water quality. Their detection and monitoring will be used to protect aquatic ecosystems, as well as drinking water supplies; there is a clear need to examine the fate of TCB and TCS following release to the environment (Cha and Cupples 2522-2530).

__Treated Wastewater Effluent versus CSO__ While treated wastewater effluent is intentionally discharged to creeks and rivers, there is unintentional untreated wastewater contaminating source water due to combined sewer overflows. Intentional discharge occurs when the wastewater has gone through screenings and treatments to disinfect waste being discharged to source water. The source water will go through a more thorough treatment process with more strict regulations and guidelines before being distributed as drinking water.

Ways for untreated water to reach groundwater may occur through pathways such as exfiltration from wastewater pipes, agricultural irrigation with treated wastewater or artificial recharge of treated wastewater to the underlying aquifer (Arye, Dror and Berkowitz 244-252). The impact of trace substances from CSO in receiving rivers is difficult to assess, since quasi-continuous measurements would be required during storm events. However, even occasional measurements of trace substances during CSO events in receiving rivers or CSO require a high sampling and analytical effort and are, therefore, rarely performed (Welker, 2007).

There are a few ways to determine whether treated or untreated wastewater has contaminated source water. There are substances that are removed in wastewater treatment plants with high efficiency, such as NTA (nitrilotriacetic acid). Finding high concentrations to occur would indicated sources from CSO. The concentration of substances that are poorly removed in wastewater treatment plants such as EDTA (ethylenediaminetetraacetic acid), decreased in CSO-influenced samples due to dilution effects. These findings have particular importance to understand water quality and for the potential importance of the CSO pathway of well-removable sewage-based trace contaminants to rivers. Compounds should be analyzed to classify both well-removable, sewage-based trace contaminants, as well as non removable compounds. An important CSO contribution of such non-persistent substances would be expected in surface waters after rain storms.

Several findings have confirmed the above findings. Benotti and Brownawell (2007) found that concentrations in a bay influenced by WWTP and CSO remained high for well-removable paracetamol and caffeine after a major storm event, while concentrations decreased clearly for all other sewage-based trace organics (Benotti and Brownawell 5795-5802). Similarly, studies have shown that well removable caffeine can be used as a tracer for untreated wastewater in streams. Their results imply that the impact of rain events on the CSO share of total annual loads of such well-removable substances may be significant (Buerge et al. 4096-4102; Buerge et al. 4096-4102). Apart from the annual contaminant influx, peak concentrations in water bodies, such as rivers or reservoirs, might be caused by CSO. Potential peak concentrations during CSO could be an important issue, since non-persistent substances typically show high biological activity.

__Sample Collection__ Sample collection is very important, since a large amount of analytical uncertainty will contribute to sample analysis. “The four basic factors which affect the quality of environmental data are sample collection, sample preservation, analyses, and recording. Improper actions in any one area may result in poor data from which poor judgments are certain”. (U.S. EPA, 1982; 3)

Since the concentration of chemicals in the sewage treatment as well as the flow of its discharge are not known, it is ideal to get a representative sample but it may be challenging.

A few approaches are presented: 1. High-Frequency Grab Sampling. There must be a high frequency of sampling to determine the highly variable flow pattern caused by distinct toilet flushes and wastewater packets from other household appliances. 2. Different Composite Sampling Modes. Since there is potential for high short term concentration variation in sewers, short sampling intervals may be required. Long term sampling may not be representive and can cause high analytical uncertainty. 3. Modeling Study. To rule out uncertainties related to sampling for particulate matter, it is better to obtain and quantify compounds in the dissolved phase to determine short-term variations. (Ort et al. 6289-6296)

An ideal way to determine the frequency of change in water qualityoOr flow is to have an online instrument, but this may be a costly approach and the technology may not always be available for the intended parameters. “The concentration of the various determinants in stream will vary due to random and systematic changes. The best technical solution, to determine the true values, would be to use an on-line automatic instrument providing continuous analyses of the determinant of interest.” (ISO, 1992;94). It is also important to denote environmental conditions, such as wet and dry conditions. Rain can impact concentrations in rivers an streams, as well as contribute to CSOs. Rain can help cause release of compounds from soil as well as dilute concentrations of analytes. Also, population of people in certain locations, amount of flushes and usage of different chemicals can be different events that occur in different locations, contributing to different water quality. It would be valuable information to survey the populations use of medications, caffeine, and pharmaceuticals to help understand the quality of the water that is expected to be produced. If flow variations are apparent, it should be taken into account during sampling to higher the sample frequency and obtain a representative 24-h composite sample.

After an established method is developed, the accuracy of the method should be shown by repeating conditions to obtain reproducible results. Sample duplicates should be collected see the variability of the sample collection and to see any variability in water quality. Analyzing replicates (subsamples) multiple times will show precision of the method. It should be acknowledged, however, that PPCPs may have times where the values are constant within a range of values, but PPCPs continue to be so variable that the sampling period should be withing a long period of time to have an idea of PPCPs behavior throughout the seasons. If there were not so many variables, it would be interesting to spike sewers with labeled reference compounds to generate a realistic PPCP pattern with a known daily mass, but it is a very challenging and almost undoable approach (Ort et al. 6024-6035).

__Proposed Monitoring Methods__ The presence of these pharmaceuticals should be confirmed through the wastewater treatment process and at locations where there is treated wastewater discharge, in order to confirm their suitability as tracers. The fates of these tracers will be quantitated through the treatment process, to ensure there isn’t complete removal from wastewater treatment. One of the wastewater sites that will be used is the Northeast Wastewater Plant (NE WWTP). The NE WWTP treats ~ 200 million gallons of wastewater per day and is also one of the oldest water pollution control plant in Philadelphia (Cheng et al. 2989-2998).

To be able to successfully monitor regulatory and compliance samples for water quality, the establishment of standards by which to judge if a discharge, stream or sample is in violation of some acceptable limit is very important. Sanders and Ward (1978) discussed a basic approach to incorporating statistics into the definition of stream standards for compliance monitoring and trend detection. Their work presented four techniques “suitable for immediate application” in water quality regulation; these were unconditional probability distribution models, seasonal probability distribution models, linear regression models and confidence intervals on probability models. Data analysis methods are an integral part of a complete monitoring program design, and should be considered at the planning stage. The information goals of a program (which could be to detect a trend, assess the effect of an intervention, or determine ambient conditions) will then largely dictate the methods of data analysis. When a trend in water quality is detected, the management of a water resource usually requires that the location of the cause be found. This can be assisted by comparing trends at different sites within a monitoring network (Dixon and Chiswell 1935-1948).

One way would like to determine wastewater contamination is by calculating mixing ratios and dilution contributions. The following approach by will be used to calculate how much contribution of wastewater is applied to source water. A model will be used to calculate the steady state dilution. This consists of wastewater effluent with a concentration of [X]ef of the tracer combining with to a stream from a pristine aquifer, having a concentration of [X]b, giving a final concentration of [X]I (Gasser et al. 398-404).

Mixing Ratio: (Effluent) / (Effluent + Pristine Water) = ( [X]i - [X]b) / ( [X]ef - [X]b )

For example, the Schuylkill River (though not pristine, will be analyzed before receiving contribution from the Wissahickon Creek) will be tested before and after it receives contribution from the Wissahickon Creek to get an idea of the amount of wastewater contribution.

Mixing Ratio: (Tracers found at Wissahickon) / (Tracers found at Schuylkill + Tracers found at Wissahickon)

Will look at trends of obtained data and comparing ratios of the three tracers to each other. Keeping in mind the fate and stability studies of the three tracers, will try to conclude a pattern to distinguish if input of wastewater to source water is due to wastewater effluent or combined sewer overflow. Data will be used to interpret the source for wastewater contamination by ratios of the three analytes. For the future, other parameters such as chlorine could be used to help interpret data, since treated wastewater should have chlorine detects. Another perspective of distinguishing water quality includes analysis of different parameters at different wastewaters to survey water quality. This may be important for the future when CSOs and water quality become a heightened issue.

A study in Paris’ watershed evaluated water quality of CSOs, wastewater, and storm water. Gasperi et al have shown that CSOs have more hydrophobic organic pollutants and particulate bound materials than wastewater and storm water, due to the contribution of in sewer deposit erosion. For Pesticides and Zinc, however, values seem to be close for all three water matrices; suggesting runoff as the major contributor, while wastewater appears to be the main source of volatile organic compounds. Monitoring CSO impact is essential since studies shown CSO discharges pose a risk for PAHs, tributyltin compounds, and chloroalakanes (Gasperi et al).

The model results were affected by significant uncertainty, which may be reduced by additional measurements (e.g. flow-proportional water quality samples to estimate the water quality parameters, on site rainfall measurements to reduce the significant input uncertainty) and by a re-formulation of the model (e.g. use of more detailed hydraulic models) (Vezzaro, Ledin and Mikkelsen ).

Would like to collect samples at areas of wastewater effluent discharge and areas of combined sewer overflow and compare water quality to help for a better understanding in the trend of data. Then will continue a monitoring program throughout the Philadelphia watershed area to see impact to source water.

__Conclusion__ The population is increasing and water supplies are becoming scarce. Utilization of recycled water wastewater has not been an issue, but is becoming an arising concern. There is also an increase use of PPCPs, and for the PPCPs to not be degraded or removed through water treatment, PPCPs are accumulating and will eventually become a toxic threat to humans and aquatic life. Reclaimed water contains unregulated contaminants of emerging concern, which include pharmaceuticals, household chemicals, personal care products, disinfection byproducts, insecticides, and suspected endocrine disruptors. (K. 69-87)

The regulations for the drinking water quality are monitored to meet state and EPA guidelines; ensuring water quality is safe for consumption and usage. Unintentional use may occur from leakages of septic tanks, sewer overflows, and droughts. When drinking water supplies had 10-50 % wastewater, they are classified as effluent impacted, while <10% contribution refers to drinking water supplies as having a low impact of wastewater contamination. High impact particularly happens when there are low flow conditions (

After determining the source of contamination, particularly CSOs, there can be additional souces for disinfection that can help reduce contamination. In addition to utilizing tracers to find wastewater intrusion, they can also be applied to asses SAT performance (Laws et al. 1087-1094).