Chapter 3: Analytical Methods/Data Sources

Transcription

1 Chapter 3: Analytical Methods/Data Sources 3.1 Introduction A large amount of data was collected and analyzed to assess the existing and future conditions in the Milwaukee Metropolitan Sewerage District (MMSD) 2020 Facilities Plan (2020 FP). These assessments were required for the development of both the 2020 FP and Southeastern Wisconsin Regional Planning Commission (SEWRPC) Regional Water Quality Management Plan Update (RWQMPU). The RWQMPU is comprised of SEWRPC Planning Report No. 50, A Regional Water Quality Management Plan Update for the Greater Milwaukee Watersheds and Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds.(1),(2) The 2020 FP and the RWQMPU are collectively known as the Water Quality Initiative (WQI). The 2020 FP is a planning document that addresses wastewater treatment, conveyance, storage, and watercourse systems throughout the MMSD planning area; it is consistent with the RWQMPU. Data was collected and analyzed from a wide range of sources to support the comprehensive approach required to develop the 2020 FP. The RWQMPU extends water quality management planning beyond the MMSD planning area and addresses water quality within the greater Milwaukee watersheds (GMW). Chapter 1, Introduction, and Chapter 2, Description of Planning Area of this report contain discussions on the structures of the 2020 FP and the RWQMPU and the relationship between the two studies. This chapter describes the major data resources and analytical methods used to evaluate wastewater treatment, conveyance, and watercourse systems for the development of the 2020 FP. 3.2 Treatment System The wastewater treatment facilities that are owned, operated, and maintained by the MMSD include the inline storage system (ISS) pump station, two treatment plants, biosolids facilities, and energy production facilities. Data was collected from the following major resources: Existing data and reports as specified in Table 3-1 Interviews with owner (MMSD) Site visits/interviews with operators (United Water Services (UWS)) Applicable tools For example: UWS daily secondary treatment capacity calculation Wisconsin Department of Natural Resources (WDNR) Applicable regulations and advisory standards A complete list of treatment system data and documents collected during the development of the 2020 FP is presented in Table 3-1 on the following page. 3-1

2 TABLE 3-1 SHEET 1 OF 6 TREATMENT SYSTEM DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

3 TABLE 3-1 SHEET 2 OF 6 TREATMENT SYSTEM DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

4 TABLE 3-1 SHEET 3 OF 6 TREATMENT SYSTEM DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

5 TABLE 3-1 SHEET 4 OF 6 TREATMENT SYSTEM DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

6 TABLE 3-1 SHEET 5 OF 6 TREATMENT SYSTEM DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

7 TABLE 3-1 SHEET 6 OF 6 TREATMENT SYSTEM DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

8 3.2.1 Flow Development The existing and future capacity requirements of the treatment facilities are established, in part, by influent wastewater flows. Thus, the existing and future projected influent wastewater flows delivered to the MMSD treatment facilities are critical to the analysis. The flows were developed based on the existing and future hydraulic capacity analysis of the conveyance system. This analysis was performed as part of the development of the Conveyance Report and other projects. The specific flows, including a discussion of existing and future flows along with methods of development, are included in Chapter 4, Treatment Assessment Existing Condition and in Chapter 5, Treatment Assessment Future Condition of the Treatment Report Wasteload Development Information regarding the volume and type of existing and future wasteloads delivered to the MMSD s treatment facilities is critical to the analysis of these facilities. Existing wasteloads were determined in Chapter 5, Treatment Assessment Future Condition of the Treatment Report by incorporating data from a number of MMSD reports, including the annual Cost Recovery Procedures Manual (3), monthly discharge monitoring reports, and daily/weekly operating reports. Future wasteloads were determined by applying residential, commercial, and industrial unit wasteload factors from the Cost Recovery Procedures Manual to average annual flows established in the Conveyance Report. The Treatment Report contains a comprehensive discussion of the MMSD treatment system. 3.3 Conveyance System The MMSD conveyance system includes the metropolitan interceptor sewer (MIS) system, the near surface collector system (NSCS), and the ISS. The conveyance system transports wastewater from the municipal collector systems to the MMSD treatment facilities. This section describes the data sources and the hydrologic and hydraulic modeling tools used to evaluate the conveyance system throughout the MMSD planning area. The MMSD conveyance system models used sewersheds as the fundamental modeling unit. There are 688 sewersheds that generate wastewater and five sewersheds that generate only stormwater throughout the MMSD existing approved sanitary sewer service area (SSSA). Chapter 2, Description of Conveyance Facilities of the Conveyance Report contains a thorough discussion of the SSSA. Each sewershed within the MMSD service area was evaluated for the following: Population Land use Major wastewater users in the sewershed Existing flow data Meteorological data Existing MMSD conveyance system facilities data 3-8

9 A comprehensive discussion of the data sources, tools and documents collected for the evaluation of the conveyance system is presented in the Conveyance Report. A summary of these data sources and tools is presented in Table Conveyance Analysis The evaluation of the MMSD wastewater conveyance system used two computer modeling tools: a sewershed flow model and a dynamic hydraulic model of the conveyance system. The sewershed flow model generates wastewater hydrographs for the sewersheds using a Flow Forecasting System program. This flow model is calibrated by using measured data to define the wastewater flow generation rates of the MMSD planning area s land use types. The conveyance system s dynamic hydraulic model is comprised of a network of pipes, pumps, and storage units. This model functions by routing the wastewater hydrographs through the computer model network to the treatment plants. The dynamic model simulates the operation of the ISS as well as combined sewer overflows and sanitary sewer overflows. The performance of the conveyance system was evaluated for existing conditions using sewershed flows generated by the population, land use conditions, and physical configuration of the conveyance system that existed in the year The future conditions were determined based on the estimated 2020 population and land use, obtained from SEWRPC. The future configuration of the conveyance system also incorporated committed projects such as the Northwest Side Relief Sewer and the North 27th Street ISS Extension. Committed projects are defined as projects and programs that MMSD is required to have fully constructed and operational by dates specified in the State of Wisconsin Circuit Court Stipulation signed May 16, 2002(4) and any non-stipulated projects under construction as of December The performance of the MMSD conveyance system was evaluated for all of the major wet weather events during the period of record. Overflow volumes were determined for those events that exceeded the ability of the system to convey flow to the treatment plants or the storage capacity of the system. 3.4 Watercourse System This section identifies data sources used to characterize surface water quality, quantity, and biological conditions for the development of the 2020 FP. A variety of data sources, based on field studies conducted from 1970 through 2004, were used to assess the historic and the baseline water quality of surface waters. These sources represent the efforts of a variety of federal, state, and local agencies and organizations. The WQI directly addresses water quality as opposed to the quantity of water or flow volumes. This planning effort does not determine or change any existing, approved watercourse system plans, including any specific floodplain analyses or delineation. 3-9

10 Data Source / Tool Description 2020 Facilities Plan Purpose Tools FFS Flow Forecasting System Generates base sanitary flow for each sewershed, computes I/I components, creates wastewater hydrographs HSPF Hydrologic Simulation Program - FORTRAN Converts rain gauge measurements and other meteorological data into runoff, infiltration, and groundwater responses Streamline-MOUSE Highly detailed hydraulic model of flow and water levelusedtosimulateindividualevents Simulates performance of the conveyance system including the ISS and discharges of CSO and SSO overflows used to identify hydraulic restrictions MOUSE Simplified version of Streamline-MOUSE Predicts discharge rates and volumes and simulates CSO and SSO hydrographs over long periods of time, such as years and decades MACRO Simple volumetric / operational model Used to simulate overall response of the system. This model is used for long-term simulations TABLE 3-2 SHEET 1 OF 2 CONVEYANCE EVALUATION DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

11 Data Source / Tool Description 2020 Facilities Plan Purpose Data Compilation SSES basins Sewer System Evaluation Survey Subunits of the separate service area that were defined as part of the Milwaukee Water Pollution Abatement Program Central MIS basins Combined sewer area sewersheds Basins that were defined during the Central MIS project Land Use -NA- Defined by SEWRPC and used to determine base sanitary flow for industrial and commercial areas Major Wastewater Users Existing Flow Data Meteorological Data MMSD Conveyance System Facilities Data Institutional and commercial users - greater than 100,000 gal / day; industrial users - greater than 250,000 gal / day Measured flow data from meters throughout the system Precipitation, solar radiation, evapotranspiration, wind speed, dew point and temperature data MMSD facilities were integrated into a Geographical Information System (GIS) Major wastewater users were added as point sources in the model This data was used to calibrate and validate the model Precipitation data was provided by the MMSD and City of Milwaukee weather stations. Other meteorological data was provided by SEWRPC. The GIS coverage of the MMSD conveyance system facilities facilitated the generation of input for the flow and hydraulic models TABLE 3-2 SHEET 2 OF 2 CONVEYANCE EVALUATION DATA SOURCES AND TOOLS 2020 FACILITIES PLAN 6/5/07 FP_3.T cdr

12 3.4.1 Surface Water Quality Milwaukee Metropolitan Sewerage District Corridor Study Database The MMSD Corridor Study Database was compiled as part of a collaborative project between MMSD, the WDNR, SEWRPC, the US Geological Survey (USGS), the University of Wisconsin-Milwaukee, Marquette University, Wisconsin Lutheran College, and other organizations to ascertain the existing state of surface water quality and ecological health of surface waters in the MMSD planning area.(5) The construction of the database commenced in February 2001 and is currently maintained by the USGS. The MMSD Corridor Study Database contains data obtained from various surface water locations, including rivers, canals, estuaries, and lakes. The database also contains data on effluent from storm sewers, municipal wastewater treatment plants, and private industrial facilities. The database contains over 2.7 million results from over 1.8 million sampling visits. The database contains essentially all of the data collected by the participating entities from 1970 to While the database includes those portions of the Lake Michigan direct drainage area within Milwaukee County and the city of Mequon, other data from Lake Michigan are not included in this database.(6) Data Sources outside the Milwaukee Metropolitan Sewerage District Planning Area Because the greater Milwaukee watersheds extend beyond MMSD s planning area, surface water quality data were also collected from outside the MMSD planning area. These data were obtained from a variety of sources, including federal, state, and local agencies, such as the USGS, the WDNR, counties, and municipalities. Additional data were obtained from citizen monitoring organizations, such as the Water Action Volunteers Program operated by the University of Wisconsin Extension, the Testing the Waters Program sponsored by Riveredge Nature Center and the Self-help Lake Monitoring Program sponsored by the WDNR.(7) In general, these data cover the period 1970 to Surface water quality data from both inside and outside the MMSD planning area were collected over the last thirty years. It is important to note that these data were obtained and analyzed for a number of different purposes using different field and laboratory methods. As a result, not all data are strictly comparable and the limits of detection and quantification along with the sampling intervals differ among data throughout the databases. Chapter III of SEWRPC Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds contains a more comprehensive description of the data used for the WQI and the limitations of these data.(8) Surface Water Quality Analysis There are hundreds of physical, chemical, and biological parameters that can be used to measure or describe surface water quality. For the WQI, several parameters were employed to evaluate surface water quality by comparing data to adopted water quality standards, which reflect specific water use objectives. To maintain consistency, these same parameters were used to evaluate the quality of point and nonpoint source discharges and ultimately to evaluate the effects of these discharges on receiving waters. The following parameters were used to characterize surface water quality: 3-12

13 Biological parameters: Fecal coliform bacteria Escherichia coli Chlorophyll-a Physical parameters: Temperature Concentration of total suspended solids Debris Chemical parameters: Alkalinity Specific conductance Hydrogen ion and nutrient concentrations Chloride Dissolved oxygen Biochemical oxygen demand Once baseline and historic conditions were established, the baseline surface water quality conditions were compared to the historic conditions to identify trends. Historic conditions were defined by the range of values observed from 1970 to Baseline conditions were defined by values observed during the period The data used for the evaluation of long-term surface water quality trends within the MMSD planning area were obtained from the MMSD Corridor Study Database. These data were supplemented with historic data taken from SEWRPC. The data were examined for trends in water quality parameter values as a function of the following: Time at a given location Location along the length of watercourses Seasons Statistically significant trends in surface water quality data over time and along the length of streams were determined by using linear regression. Date and river mile (location) were the independent variables in the regression analysis. Some of the water quality data were logtransformed to meet the normality requirements for regression analysis. A trend was determined to exist when there was a statistically significant regression coefficient with a probability less than or equal to five percent (P 0.05). Seasonal changes were examined through graphical analysis. By plotting a large number of data points on graphs, analysts were able to visually discern seasonal effects on historic and baseline surface water quality. Chapters V through X of SEWRPC Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds contain more detail on the analysis of seasonal changes. 3-13

14 The average values of specific surface water quality parameters were compared between upstream stations and the estuary. In Milwaukee, the estuary is the body of water where the Menomonee, Milwaukee, and Kinnickinnic Rivers meet and mix with Lake Michigan.(9) The assessment and comparison of water quality parameters among upstream stations and the estuary was performed by using analysis of variance (ANOVA). The ANOVA is used to test for significant differences between the means of two or more groups of data. For the comparison of surface water quality between upstream stations and the estuary, water quality data is presented during four time intervals: (includes winter-time sampling; this was discontinued in 1986) (data collected before ISS was brought into service) (data collected after ISS was brought into service) (data collected after ISS was brought into service; interval also represents baseline conditions) These intervals were chosen to reflect major changes in the infrastructure available to the MMSD as well as changes in data collection procedures used by MMSD. For each interval, ANOVAs were conducted for each surface water quality parameter for which sufficient data were available. Chapter III of SEWRPC Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds contains a more comprehensive description of water quality data and analytical methods used for the WQI Sources of Pollution to Surface Water The SEWRPC staff obtained lists of discharge permits issued under the Wisconsin Pollution Discharge Elimination System (WPDES) that were effective in February These included lists of permits for discharges from public and private wastewater treatment plants, permits issued under the general permit program for discharges from industrial and related facilities and municipal wastewater collection systems, individual permits issued for discharges from industrial and related facilities, and permits issued for discharges of stormwater. Pollutant loadings were developed through watercourse modeling, based on a review of historical data and discharge permit reported discharge data reported in accordance with the discharge permits listed above. The modeling procedures are described in Chapter III of SEWRPC Technical Report No. 39, A Regional Water Quality Management Plan Update for the Greater Milwaukee Watersheds.(10) Data from three types of point sources were included in the model: public and private wastewater treatment facilities, facilities permitted to discharge noncontact cooling water under the WPDES general permit program, and facilities with individual permits under the WPDES individual permit program. Monitoring data were obtained from reports submitted to WDNR. Nonpoint source pollutant loads were estimated through the application of the Loading Simulation Program in C++ (LSPC) water quality model. Locations of the sewer bypasses and overflows, along with data on bypass dates and volumes, were obtained from the MMSD for sites located within the MMSD planning area. The WDNR provided data on bypass sites that were located outside of the MMSD planning area. 3-14

15 3.4.4 Surface Water Quantity Since 1970, the USGS has operated 61 streamflow stations within the six watersheds that comprise the GMW. Chapter 2, Description of Planning Area of this report contains a discussion of the GMW. Forty-two of these stations are located within the MMSD planning area. These stations record stream elevation relative to an arbitrary reference point on a continual basis. Measurements are also made of the streamflow or discharge that passes the stream cross section. This information is used to develop a rating curve that relates stream stage to streamflow. In addition to USGS data, MMSD also has collected water surface elevation data at four sites within the MMSD planning area since With the exception of the Lake Michigan direct tributary drainage area, all of the watersheds in the MMSD planning area have at least one streamflow station. Chapters V through X of SEWRPC Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds contain a detailed discussion and mapping of the locations of the specific streamflow stations used for the WQI. A flow fraction represents a comparison of median flow at a hypothetical station to the median flow at a reference station in a downstream section of the same river. Flow fraction was determined for each station for which flow data existed in order to compare the flow at various locations in each watershed and to estimate the contribution of each tributary to the downstream volume. Flow Fraction Calculation For each station, the flow fraction was derived by calculating the median flow for the period of record. This number was then divided by the median flow from the reference station, for the same time period. The median was used because it is less sensitive to outliers (extreme values) than the arithmetic mean. Although this type of analysis has some limitations, such as limited recognition of the variability contained within the flow data, and the lack of sensitivity to processes such as evapotranspiration or groundwater interactions, the analysis serves to provide an approximation of the relative magnitudes of flow at various locations within a watershed Biological Conditions in Surface Water Fisheries data were obtained from databases constructed and maintained by the WDNR. Historic fishery sampling records were obtained from the Master Fish File.(11) More recent data were obtained from the National Biological Database.(12) In addition, the Wisconsin Lutheran College and the University of Wisconsin Milwaukee supplemented the WDNR fish monitoring data.(13) Surveys of stream macroinvertibrates were obtained from the WDNR through the Bug Monitoring Database constructed and maintained for the WDNR by the University of Wisconsin- Stevens Point.(14) Additional data were obtained from stream invertebrate monitoring conducted by Wisconsin Lutheran College and by citizen monitoring programs where such data were judged to be adequate.(15) An Index of Biotic Integrity (IBI) specific to Wisconsin, was used to classify the fisheries and environmental quality in the streams in the WQI study area.(16) The IBI consists of a series of 3-15

16 fish community attributes that reflect the characteristics of biotic assemblages: species richness and composition, trophic and reproductive function, individual abundance, and condition. The biological assessment rating for stream macroinvertebrate taxa is based upon modified rapid bioassessment protocol criteria for screening water quality that includes a number of benthic community attributes. Examples of benthic community attributes that are considered include taxa richness (total number of families) and percent dominance (percentage of total number of individuals in the sample belonging to a numerically dominant family). These parameters respond to a variety of stressors, including organic pollution, low dissolved oxygen, toxic contaminants, flow disruption, and thermal stress. The assessment characterizes the state of stream sites as being nonimpaired, moderately impaired, or severely impaired based upon the composition of the benthic macroinvertibrate community. Chapters V through X of SEWRPC Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds contain a detailed discussion and mapping of the fisheries and macroinvertebrate sampling sites used for the WQI Stream Habitat Conditions The SEWRPC used a variety of physical habitat parameters to classify the quality and diversity of available habitat for fish and other aquatic organisms. The WDNR has recently developed guidelines for evaluating habitat of streams as part of their baseline monitoring protocol.(17) This protocol measures a variety of parameters that include streamflow, water depths, width, substrate composition, sinuosity, gradient, and amounts of pool and riffle habitat. To enable direct comparison, these habitat assessments were conducted for the same sites for which the fisheries assessments were completed. Chapters V through X of SEWRPC Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds contain maps and additional discussion of specific habitat assessment locations used for the WQI Riparian Corridor Conditions Riparian corridors were delineated based on the presence of natural vegetation, as shown on the year 2000 SEWRPC digital orthophotographs.(18) The areas were mapped using a geographical information system. The riparian widths were classified based on the average distance between the edge of the stream channel and the exterior border. For each stream reach or segment evaluated, the average riparian width was evaluated for both the left and right bank and was placed into one of four categories: 0-25 feet feet feet Greater than 75 feet 3-16

17 3.5 Digital Library The Digital Library was designed as a repository of information used to complete the 2020 FP planning process and was intended to collect, organize, and structure data to allow users to effectively search for information. An online catalog format, organized by information specialists, was developed for the library. This gave planners a single point of reference for all the historical data used for the 2020 facilities planning process and minimized the chance that different data were referenced during the planning process. 3-17

18 References (1) Southeastern Wisconsin Regional Planning Commission, Planning Report No. 50, A Regional Water Quality Management Plan Update for the Greater Milwaukee Watersheds (Draft January 31, 2005: chapter in progress) (2) Southeastern Wisconsin Regional Planning Commission, Technical Report No. 39, Water Quality Conditions and Sources of Pollution in the Greater Milwaukee Watersheds (Draft September 2, 2005: chapter in progress) (3) Milwaukee Metropolitan Sewerage District, 2006 Cost Recovery Procedures Manual, available from MMSD offices, located at 260 West Seeboth Street, Milwaukee, Wisconsin (4) State of Wisconsin, Circuit Court, Milwaukee County (2002), State of Wisconsin, Plaintiff vs. Milwaukee Metropolitan Sewerage District, Defendant, Case No. 02-CV (Stipulation filed May 29, 2002) (5) Morgan A. Schneider, Michelle A. Lutz et al., Water Resources Related Information for the Milwaukee Metropolitan Sewerage District Planning Area, Wisconsin , U.S. Geological Survey Water Resources Investigation Report , 2004 (6) Southeastern Wisconsin Regional Planning Commission, Technical Report No. 39, Data Sources and Methods of Analysis, Chapter III (Draft September 2, 2005, chapter in progress, Page 2) (7) Ibid., Page 3 (8) Ibid. (9) Southeastern Wisconsin Regional Planning Commission, Planning Report No. 50, A Regional Water Quality Management Plan Update for the Greater Milwaukee Watersheds, Chapter I (Draft June 23, 2006, chapter in progress, Page 3) (10) Southeastern Wisconsin Regional Planning Commission, Technical Report No. 39, Data Sources and Methods of Analysis, Chapter III (Draft September 2, 2005, chapter in progress, Page 12) (11) Southeastern Wisconsin Regional Planning Commission, Technical Report No. 39, Data Sources and Methods of Analysis, Chapter III (Draft September 2, 2005, chapter in progress, Page 4) (12) Ibid. (13) Ibid. (14) Ibid., Page 5 (15) Ibid. (16) Ibid., Page 13 (17) Ibid., Page

19 (18) Digital orthophotographs available on CD-ROM from Southeastern Wisconsin Regional Planning Commission, W239 N1812 Rockwood Drive, Waukesha, WI