System Characterization and Monitoring Activities Julia Moore, P.E. Limno-Tech, Inc.

System Characterization and Monitoring Activities 2 Expectations of the CSO Policy The purpose of system characterization [and] monitoring… is initially to assist the CSO community with implementation of the NMCs, and, if necessary, to support development of a LTCP.

System Characterization and Monitoring Activities 3 Objectives Develop an understanding of the combined sewer system (CSS) and receiving waters Assess CSS design and operating conditions Characterize combined sewage and CSO impacts on receiving waters Identify gaps in existing information and plan activities to address them Assist with implementation of the NMC

System Characterization and Monitoring Activities 4 Three Components of System Characterization Physical characterization of CSS Characterization of combined sewage and CSOs Characterization of receiving waters

System Characterization and Monitoring Activities 5 Physical Characterization Key sources of existing information Sewer maps, design specifications, as-built drawings CSS, pump station, and WWTP flow records National Climate Data Center (NCDC) rainfall records

System Characterization and Monitoring Activities 6 Physical Characterization Additional sources of existing information WWTP facilities plans Pump station and WWTP performance data (e.g. stress test results) Treatment plant upgrade reports Infiltration/inflow (I/I) studies Sewer system evaluation surveys (SSES) Storm water master plans GIS databases

System Characterization and Monitoring Activities 7 Physical Characterization LTCP development typically includes: Delineation of CSS area and sewersheds Location of CSO outfalls and regulator structures, the WWTP, and pump stations Description of CSO receiving water Land use and estimated impervious cover, by sewershed Layout of major interceptors Hydraulic capacities for the WWTP, CSO regulators, and pump stations

System Characterization and Monitoring Activities 8 Physical Characterization of Springfield, USA Delineation of CSS area CSO outfall locations Receiving waters Lazy River Babbling Brook CSS Area Separate Sewer Area Satellite Community

Lazy River Babbling Brook CSO Area #1 (300 acres) CSO #3 CSO #1 CSO #2 CSO Area #3 (150 acres) CSO Area #2 (250 acres) CSO #4 Pump station relief CSO Area 9

System Characterization and Monitoring Activities 10 Physical Characterization Layout of major interceptors Location of: WWTP CSO regulators Pump station WWTP

System Characterization and Monitoring Activities 11 Physical Characterization General land use and estimated impervious cover Land use categories include: Parkland or open space (<5% impervious) Low density development (5-35% impervious) Medium density development (35-70% impervious) High density development (>70% impervious)

High Density Medium Density Low Density Open Space System Characterization and Monitoring Activities 12

System Characterization and Monitoring Activities 13 Land Use Tabulation Parkland/ Open Space Low Density Development Medium Density Development High Density Development CSO Area #1 25%40%25%10% CSO Area #2 10%25%45%20% CSO Area #3 5%15%30%50%

System Characterization and Monitoring Activities 14 Impervious Cover Calculation Example: CSO Area #1 includes : 25% park (3% impervious)0.8% 40% LDD (25% impervious)10.0% 25% MDD (50% impervious)12.5% 10% HDD (75% impervious)7.5% Average Impervious Cover:30.8%

System Characterization and Monitoring Activities 15 Physical Characterization Hydraulic analysis should be sufficient to: Establish capacities for WWTP, pump stations and CSO regulators Quantify dry weather and wet weather flows, including flows to CSS from neighboring communities Describe any existing flow metering Permanent system meters and monitors such as SCADA (Supervisory Control And Data Acquisition) Metering/flow monitoring from previous studies Identify problem areas and bottlenecks

System Characterization and Monitoring Activities 16 Pump Station and WWTP Capacities (MGD) WWTP Average daily flow rate CSS area Separate sewer area Satellite communities Primary treatment capacity Secondary treatment capacity Pump Station Average daily flow rate Maximum pump rate

System Characterization and Monitoring Activities 17 CSS Capacities (MGD) CSO Area #1 Dry weather flow rate Regulator capacity CSO Area #2 Dry weather flow rate Regulator capacity CSO Area #3 Dry weather flow rate Regulator capacity

System Characterization and Monitoring Activities 18 Flow Balance Q wet = CiA CSO Area #1 wet weather runoff (30.8% impervious) x (1” rain) x (300 acres) = 2.5 mg runoff per inch of precipitation CSO Area #2 wet weather runoff (43.8% impervious) x (1” rain) x (250 acres) = 3.0 mg runoff per inch of precipitation CSO Area #3 wet weather runoff (56.4% impervious) x (1” rain) x (150 acres) = 2.3 mg runoff per inch of precipitation C = runoff coefficient (% imperviousness) i = rainfall intensity A = area

Flow Balance Diagram 19

Flow Balance Diagram 20

System Characterization and Monitoring Activities 21 Problem Areas and Bottlenecks Compare capacity at key locations in the collection system with peak wet weather flow rates Intersections of major interceptors Regulators Pump stations Cross connections Additional study may be required in areas that often flood during wet weather

System Characterization and Monitoring Activities 22 Example—Bottleneck Pump station capacity should equal or exceed capacity of interceptors delivering flow to WWTP From CSOs #1 and #3 From CSO #2 P.S. capacity 6 MGD Max. flow = 5.5 MGD Max. flow = 2 MGD

System Characterization and Monitoring Activities 23 Characterization of Combined Sewage and CSOs Sources of existing information: General WWTP operating data Discharge monitoring reports (DMRs) Pretreatment program data Facility planning studies GIS databases Other local CSO studies Literature

System Characterization and Monitoring Activities 24 Characterization of Combined Sewage and CSOs LTCP should include estimates of central tendency (median, EMC) and ranges of concentration for pollutants of concern Most often: Bacteria, TSS, BOD Sometimes: Nutrients Less often: Metals and toxics

System Characterization and Monitoring Activities 25 Average Pollutant Concentrations in Municipal Discharges Fecal Coliform (MPN/100mL) SourceRangeMedian Untreated wastewater10 6 – Wet weather SSOs--500,000 CSOs3 – ,000 Urban storm water1 – ,081 Treated wastewater--<200

System Characterization and Monitoring Activities 26 Average Pollutant Concentrations in Municipal Discharges BOD 5 (mg/L) SourceRangeMedian Untreated wastewater88 – Wet weather SSOs6 – CSOs4 – Urban storm water0.4 – Treated wastewater--30

System Characterization and Monitoring Activities 27 Average Pollutant Concentrations in Municipal Discharges TSS (mg/L) SourceRangeMedian Untreated wastewater118 – Wet weather SSOs10 – CSOs1 – 4, Urban storm water0.5 – 4,80058 Treated wastewater--30

System Characterization and Monitoring Activities 28 Characterization of Receiving Waters Sources of existing information: Applicable state water quality standards USGS streamflow data EPA STORET and BASINS Programs State 305(b) Water Quality Assessment Reports State 303(d) lists of impaired waters Other local water quality assessments

System Characterization and Monitoring Activities 29 Characterization of Receiving Waters LTCP should document the following: Designated uses for each CSO-impacted water Available water quality, sediment, and biological data Flow conditions in the CSO receiving water(s) Known impairments Location of sensitive areas Planned or ongoing TMDL studies

System Characterization and Monitoring Activities 30 Example Designated Use Lazy River Secondary Contact Recreation – Used for power boating, sail boating, canoeing and rowing for recreational purposes when surface water flow or impoundment conditions allow Nontrout Water – Suitable for propagation and survival of fish

System Characterization and Monitoring Activities 31 Example Water Quality Criteria Lazy River Dissolved Oxygen –the minimum daily average shall not be less than 5.0 mg/L, and at no time shall the DO concentration be less than 4.0 mg/L Bacteria – the monthly geometric mean, from a minimum of five examinations, shall not exceed 200 MPN/100 mL during all periods when disinfection is practiced pH – from 6.5 to 8.5, inclusive Garbage and other refuse – none in any amounts

System Characterization and Monitoring Activities 32 Example Summary of Available Water Quality Data StatisticsDO (mg/L) Fecal Coliform (May-Sept) (MPN/100mL) Fecal Coliform (Oct-Apr) (MPN/100mL) pH Minimum Maximum12.711,0009, Average8.91,3961, Median8.62,3061, % of time WQS violated 081.8%012.6% Water Body – Lazy River

System Characterization and Monitoring Activities 33 Example Designated Use Babbling Brook Potable Water Supply – Used, after conventional treatment, for drinking, culinary and other domestic purposes, such as inclusion into foods, either directly or indirectly Primary Contact Recreation – Used for swimming and other full-body contact activities Trout Water – Suitable for propagation and survival of fish, including trout

System Characterization and Monitoring Activities 34 Example Water Quality Criteria Babbling Brook Dissolved Oxygen – the minimum daily average shall not be less than 6.0 mg/L, and at no time shall the concentration be less than 5.0 mg/L Bacteria – the monthly geometric mean, from a minimum of five examinations, shall not exceed 200 MPN/100 mL pH – from 6.5 to 8.5, inclusive Garbage and other refuse – none in any amounts

System Characterization and Monitoring Activities 35 Example Summary of Available Water Quality Data StatisticsDO (mg/L) Fecal Coliform (MPN/100mL) pH Minimum Maximum14.713, Average Median % of time WQS violated 057.9%3.4% Water Body—Babbling Brook

System Characterization and Monitoring Activities 36 Example Summary of Flow Conditions Station IDStation Name PeriodDrainage Area Lazy River at Springfield 1946-present314 sq. mi Babbling Brook at Shelbyville 1973-present13.9 sq. mi.

Example Summary of Flow Conditions MonthLazy River (cfs) January642 February642 March757 April734 May610 June450 July402 August269 September289 October306 November375 December547 Average461 cfs 37

System Characterization and Monitoring Activities 38 What if Local Flow Data are Not Available? Options for estimating flow: Scale down/up from gage elsewhere in the watershed Use data from similar local watershed with gage Estimate flow using Q=CiA

Example Scale Up from Another Gage Springfield CSO Area X Shelbyville Gage on Babbling Brook 39

System Characterization and Monitoring Activities 40 Example – Scale Up from Another Gage Babbling Brook at Shelbyville Drainage Area 13.9 mi 2 Annual Average Flow 9.9 cfs Babbling Brook at Springfield Drainage Area 17.2 mi 2 Annual Average Flow 17.2 mi 2 = BB flow 13.9 mi cfs BB flow = 12.2 cfs

System Characterization and Monitoring Activities 41 Example Summary of Known Impairments The State 303(d) list includes water bodies where existing pollution control activities are not sufficient to attain applicable WQ standards. The list includes several water bodies that pass through Springfield. Lazy River within Springfield is listed for dissolved oxygen/ oxygen demand, pH, and floatables (NOT bacteria). Babbling Brook from the county line to its mouth at the Lazy River is listed for bacteria and floatables. Upstream portions of the brook are also listed for bacteria.

System Characterization and Monitoring Activities 42 Characterization of Receiving Waters Sensitive areas per CSO Policy include: Outstanding National Resource Waters National Marine Sanctuaries Waters with threatened and endangered species and their habitat Primary contact recreation waters, such as beaches Public drinking water intakes Shellfish beds Sensitive area descriptions should include locational information (e.g., river mile or narrative based on known upstream/downstream distance)

System Characterization and Monitoring Activities 43 Example Identification of Sensitive Area Babbling Brook has a designated use of primary contact recreation. Jebediah Springfield Beach is located on the northeast shore of the brook, approximately 0.3 miles downstream of CSO #1 and 0.1 miles above the confluence with the Lazy River. Jebediah Springfield Beach is open to the public for swimming and wading weekends from Memorial Day to Labor Day.

System Characterization and Monitoring Activities 44 Monitoring Program Builds on the system characterization Designed to obtain missing, but necessary, information about the CSS operating conditions and CSO impacts Supports implementation of both the NMC and an LTCP

System Characterization and Monitoring Activities 45 Expectations of the CSO Policy The permittee should develop a comprehensive, representative monitoring program that measures the frequency, duration, flow rate, volume and pollutant concentration of CSO discharges and assesses the impact of CSOs on the receiving water…

System Characterization and Monitoring Activities 46 Monitoring Goals and Objectives Typical objectives: Define hydraulic response of the CSS to rainfall Determine CSO impacts on receiving water(s) Establish baseline conditions to characterize long-term effects of CSO controls Evaluate effectiveness of the NMC

System Characterization and Monitoring Activities 47 Monitoring Program Documentation Identify monitoring goals and objectives Identify data needs Demonstrate that sampling program addressed data needs Document method for data management and analysis

System Characterization and Monitoring Activities 48 Monitoring—Data Needs Data needs are very site specific Closely linked to short and long-term control objectives Data needs are dependent on the amount of existing information available Prioritization often required as data needs are typically greater than available budget Monitoring should be conducted in a manner consistent with applicable state water quality standards

System Characterization and Monitoring Activities 49 Monitoring - Costs Usually only 20 to 50 percent of CSOs need full monitoring in a system Cover range of land use Pick largest and/or unique CSOs Monitoring is expensive Models “stretch” the value of monitoring

System Characterization and Monitoring Activities 50 Monitoring—Sampling Program Types of monitoring: Rain gage CSS flow Dry weather Wet weather CSO volume, frequency and pollutant concentrations Receiving water monitoring Upstream CSO impacted zone

System Characterization and Monitoring Activities 51 Monitoring—Sampling Program Sampling parameters: Flow CSO effluent and receiving water quality Bacteria, TSS, BOD Nutrients (if needed) Metals and toxics (if needed) Continuous vs. discrete event monitoring

System Characterization and Monitoring Activities 52 Monitoring Location Selection Physical logistics and budget Flow patterns and spatial variability between with storms Pollutants of concern; location of sources Location of sensitive areas

Example of Rainfall Variability System Characterization and Monitoring Activities 53 8/10 – 8/12/01 Radar Rainfall Estimates

Screening Potential CSS Monitoring Locations Outfall #Area (acres) Landuse Access/ Safety Concerns Sensitive Area Potential Monitoring Location Open/ Park Low Density Med. Density High Density %40%25%10%Xyes %25%45%20%Xno %15%30%50%yes 4 0N/A Xyes System Characterization and Monitoring Activities 54

System Characterization and Monitoring Activities 55 Example CSS Monitoring Locations Rain gage location Electronic meter location Block test location Rain gage at local airport WWTP

System Characterization and Monitoring Activities 56 Monitoring—Sampling Program Information to be documented: Duration of monitoring program Monitoring locations Frequency of sampling; number of events sampled Pollutants or parameters analyzed Sampling protocols, equipment used and analytical methods

System Characterization and Monitoring Activities 57 Example Block Test Results OutfallLocationPeriodResults #4 - pump station relief Foot of Leesome Lane 01/01 – 09/30At least 22 overflow events

Electronic Meter Results System Characterization and Monitoring Activities 58

Example Receiving Water Monitoring Locations Weekly water quality monitoring station Wet weather survey station System Characterization and Monitoring Activities 59

System Characterization and Monitoring Activities 60 Grab Samples vs. Continuous Monitoring Grab sampling Can be less expensive Can be simple Only represents a single point in time Continuous monitoring Labor and/or resource intensive Requires specialized equipment & attention Highly programmable Allows accurate characterization of water quality integrated over time or flow volume

Example Monitoring System Characterization and Monitoring Activities 61

System Characterization and Monitoring Activities 62 Example Monitoring Results Receiving Water Boundary Conditions ParameterUnitsBabbling Brook Event Mean Concentrations Base flowStorm flow BODmg/L TSSmg/L1294 Fecal coliform MPN/100mL 9803,800

System Characterization and Monitoring Activities 63 Special Characterization Studies Additional studies may be needed in areas where CSOs are causing substantial water quality impacts Sediment studies Whole effluent toxicity testing Biological assessments Industrial contributions

System Characterization and Monitoring Activities 64 Summary System Characterization Physical characterization of CSS Characterization of combined sewage and CSOs Characterization of receiving waters

System Characterization and Monitoring Activities 65 Summary Monitoring Track frequency, duration, flow rate, volume and pollutant concentration of CSO discharges Evaluate impacts of CSOs on the receiving water