2008 “follow-up” sampling program final report

The Neponset River Watershed Association

2008 “Follow-up” Sampling Program Final Report

January 20, 2009 Bill Guenther, Environmental Scientist

Contents

Acknowledgements 1

Project Purpose 1

Project Scope and Methodology 1

Germany Brook Results, Norwood 3

Hawes Brook Results, Norwood 7

Plantingfield Brook Results, Norwood and Westwood 13

Purgatory Brook Results, Norwood and Westwood 17

Neponset River Results, Boston and Milton 21

Appendix A: Data Quality Objectives and QC Data for E.coli, Ammonia and Surfactants 25

Neponset River Watershed Association, Follow Up Sampling 2008, page 1

Acknowledgements The Neponset River Watershed Association (“the Association”) would like to thank the CHT Foundation, the George H. and Jane A. Mifflin Memorial Fund, the Amelia Peabody Charitable Trust, Analog Devices, and the Copeland Family Foundation, as well as the individual and corporate members of the Association whose support and generosity made the 2008 Follow-up Sampling Program possible. We would also like to recognize the additional support and assistance of the Milton Department of Public Works, Boston Water and Sewer Commission, Westwood Department of Public Works, Massachusetts Water Resources Authority, Mass Department of Environmental Protection, USEPA and more than 70 neighborhood volunteers who have made the larger Neponset Citizen Water Monitoring Program possible.

Project Purpose The Association’s Citizens’ Water Monitoring Network or “CWMN” program uses a volunteer based approach to monitor water quality at 41 instream locations throughout the watershed six times a year. The data collected in that program is analyzed and streams that repeatedly show poor or deteriorating water quality are prioritized for inclusion in the Association’s Follow-up Sampling Program. Under the Follow-up Program, Association staff implement a higher resolution sampling plan tailored to the unique conditions on each problem stream. This generally involves shoreline surveys and the collection of additional samples both instream and at storm drain outfalls, in an effort to locate specific sources of pollution contributing to impairment of the stream.

2008 Project Scope and Methodology Several new stream reaches were selected for inclusion in the 2008 Follow-up Program. In addition, one previously sampled reach was carried forward for additional testing. The new areas for 2008 were Hawes Brook and its tributary, Germany Brook located in Norwood; Purgatory Brook and its tributary Plantingfield Brook located in Westwood and Norwood; and the section of the Neponset River from the Tileston and Hollingsworth Dam to the Baker Dam located between Hyde Park and Milton/Dorchester Lower Mills. Limited sampling was also conducted along the Neponset River between Paul’s Bridge / Neponset Valley Parkway and the Tileston and Hollingsworth Dam where several problem outfalls had previously been identified during 2007. Data from the larger CWMN Program indicates that each of these reaches shows elevated levels of instream bacterial pollution during dry weather. For each of these streams, the Association suspected that sewage was finding its way into the stream through some combination of illicit connections, sewer system exfiltration or other mechanisms. Accordingly, the study design for 2008 involved conducting shoreline surveys of each stream to visually identify potential dry weather bacterial pollution sources, followed by sampling both


instream and at any flowing storm drain outfalls during dry weather (minimum 72 hours with no precipitation). Samples were collected by Association staff using an opportunistic sampling location selection approach. Sampling locations were documented using a handheld GPS. Samples were analyzed for E.coli bacteria, surfactants (i.e. detergents) and ammonia. Samples were also tested for pH and conductivity. All samples were analyzed by Association staff in accordance with the Association’s DEP / EPA approved Quality Assurance Project Plan and in accordance with the Standard Operating Procedures laid out therein for sample collection and analysis. Samples were collected and preserved in the field for all parameters, and analyzed in the laboratory at the Association office. Conductivity and pH were analyzed using appropriately calibrated meters. E. coli was measured using the Colilert method. Ammonia was analyzed using a Chemetrics V2000 handheld photometer and reagent kit with detection range of 0.1 to 3.0 ppm. Surfactants were tested using a Chemetrics colorimetric test kit with a detection range of 0 to 3.0 ppm. In interpreting the results, any outfall with bacteria counts above the MA Surface Water Quality single sample E. coli threshold of 235 CFU/100 ml is considered cause for concern. Surfactant values of 0.25 ppm or greater and Ammonia values of 0.15 ppm or greater were also cause for concern. Per EPA recommendations, anytime two, or particularly three, of these indicators are found above these thresholds, it is considered very likely that sewage pollution is present.


Germany Brook Results Germany Brook is a small tributary to Ellis Pond and Hawes Brook, located in Norwood (Figure 1). Site GEB102 is located between sites GEB101 and GEB103. The GPS device used to plot site coordinates was unable to lock onto satellites at the time of sampling or during subsequent site visits. CWMN data for Germany Brook shows a consistent and serious problem with wet weather water quality, especially for bacteria. It also shows a modest problem with dry weather bacteria. Samples were taken from several outfalls discharging to the brook during dry weather as well as instream (Table 1). Only one instream sample was above the single sample standard for E.coli. This instream site was upstream of the one questionable outfall that was identified along this reach. Of the several outfalls that were sampled along Germany Brook, only GEBout02 exceeded the single sample standard for E.coli. Although GEBout02 had elevated bacteria every time it was sampled, it showed no indication of ammonia or surfactants. Further investigation is required along Germany Brook to better characterize both the extent of the bacteria pollution as well as its possible sources, particularly during wet weather. Germany Brook will continue to be sampled as part of the CWMN program and the results closely monitored. Further investigation of outfall GEBout02 should also be conducted. The Association may include Germany Brook in planned optical brightener testing and further bacteria testing during 2009. The town should undertake further investigations inside the drain system at outfall GEBout02.


Figure 1: Sampling locations along Germany Brook in Norwood, MA, 2008.


Table 1: Data collected from Germany Brook in Norwood, MA, 2008.

Sample ID

Date E.coli (MPN/100mL)

Ammonia (mg/L)

Surfactants (mg/L)

pH Conductivity (µs)

GEB101 7/30/2008 435.2 0.065 0.00 7.44 586 GEB101 8/20/2008 118.7 0.000 0.00 7.88 685 GEB101 9/17/2008 125.9 0.085 0.00 7.66 508

GEB102 8/20/2008 88.2 0.072 0.00 7.86 554

GEB103 8/20/2008 63.1 0.038 0.00 6.43 627

GEBout01 7/30/2008 37.9 0.000 0.00 7.21 542 GEBout01 8/20/2008 24.9 0.109 0.00 7.81 551 GEBout01 9/17/2008 0.0 0.000 0.00 7.42 558

GEBout02 7/30/2008 328.2 0.000 0.00 7.33 735 GEBout02 8/20/2008 387.3 0.000 0.00 7.35 549 GEBout02 9/17/2008 1,986.3 0.000 0.00 7.63 683

GEBout03 8/20/2008 63.7 0.000 0.00 7.21 556

GEBtrib 8/20/2008 113.7 0.015 0.00 6.62 525


Hawes Brook Results Hawes Brook, like Germany Brook, is located in Norwood, MA. It originates at the outlet of Willett Pond and ends at the Neponset River (Figure 2). CWMN data show that the upper reaches of Hawes Brook have moderate wet weather bacteria problems and intermittent dry weather problems. At the two downstream CWMN stations on Hawes Brook, both wet weather and dry weather problems are more consistent and pronounced, intensifying as you move further downstream. Sampling was conducted instream along Hawes Brook and at outfalls flowing during dry weather. As the investigation progressed, it came to focus primarily on a small unnamed tributary to Hawes Brook. The unnamed tributary originates at a culvert located on town property off of Wilson Street and terminates at Hawes Brook upstream of the railroad tracks adjacent to Endean Park in Norwood, MA (Figure 2). Preliminary sampling showed that the unnamed tributary was clearly a major contributor to the high bacteria levels in Hawes Brook (Table 2). Once it was established that there were consistently high bacteria levels in the unnamed tributary, samples were taken with more frequency in the tributary in an attempt to track the source of the pollution. Tracking continued in the tributary until finally the origin of the tributary was located in the aforementioned town land off of Wilson Street. Samples were taken at intervals along the tributary. Results showed some variation but almost all instream samples from the tributary had elevated levels of bacteria well over the Massachusetts Surface Water Quality standard for E.coli. There do, however, appear to be two “hot spots” along the unnamed tributary where E.coli levels are higher than elsewhere along the brook. These areas are located near the confluence of the tributary and Hawes Brook (HABtrib01, 02, 03) and also in the headwaters of the tributary near, but not at, the culvert where the tributary emerges from under Arcadia Rd. (HABtrib12) in Norwood, MA (Table2). Levels of bacteria at these locations were consistently higher than levels from locations elsewhere along the tributary. HABtrib12 also had one sample with elevated ammonia. Similar to the outfall along Germany Brook, the unnamed tributary exhibited repeated instream samples with high bacteria levels but little or no elevated levels of the corroborating parameters such as ammonia or surfactants. Nevertheless there was no evidence of concentrations of wildlife or other non-human sources that might explain the high instream bacteria levels. Further sampling within this tributary for human markers, such as caffeine or optical brighteners should be attempted to better ascertain whether or not the bacteria pollution is anthropogenic. It should be noted that outfalls along the unnamed tributary are normally inundated so it is impossible to tell if there may be illicit connections at these locations at this time. Therefore, further investigation inside the surrounding drainage system is recommended. Only one outfall flowing during dry weather was observed along Hawes Brook proper, at HABout01, and it was only found to be flowing during one of multiple visits. However, the one sample that was collected at the outfall was over the water quality standard for bacteria by an


order of magnitude. Low levels of ammonia were also detected. The outfall in question is located adjacent to the sewer manhole topped with a large concrete block (described further below). This outfall merits further testing and the town should undertake investigation inside this drain system. Historically, the Association has observed repeated activation of a sanitary sewer overflow at one in a series of manholes which run along Hawes Brook between Washington Street and the railroad track. Activation of this SSO has historically involved the manhole cover being dislodged by water exiting from the sewer. The manhole in question is located adjacent to HAB0ut01 mentioned above. More recently the Association has observed that someone has placed a large concrete block on top of this sewer manhole in an apparent attempt to fix the sanitary sewer overflow. On December 11, 2008 Norwood experienced a significant rain event, roughly 3.5” of rain over 18 hours. Association staff visited the “weighted manhole cover” following the storm. As is shown in the included photos (Figures 3 through 6), Association staff observed sewage exiting the “weighted manhole” in spite of the weight. We also observed overflows occurring at the next manhole upstream and downstream along the same sewer line. As a result, a substantial length of the public walking/cycling trail through the park was occupied by a standing pool of sewage and floodwater. While we were making these observations, a cyclist rode through the puddle. Further investigation and remediation of this SSO by the town is recommended, as is posting of appropriate signage by the Board of Health as an interim measure.


Figure 2: Sampling locations along Hawes Brook and its tributary in Norwood, MA, 2008.


Table 2: Data collected from Hawes Brook in Norwood, MA, 2008

Sample ID Date E.coli

(MPN/100mL) Ammonia

(mg/L) Surfactants

(mg/L) pH Conductivity

(µs) HAB1001 6/17/2008 101.9 0.000 0 7.23 341.0 HAB1002 6/17/2008 146.7 0.000 0 7.23 342.0 HAB1003 6/17/2008 131.4 0.000 0 7.12 345.0 HAB1003 9/17/2008 79.9 0.000 0 7.23 365.0

HAB1004 6/17/2008 387.3 0.055 0 7.01 347.0 HAB1004 9/17/2008 249.5 0.023 0 7.65 408.0

HABout01 6/17/2008 2,143.0 0.026 0 7.04 377.0

HABtrib01 6/17/2008 1,119.9 0.044 0 7.28 523.0 HABtrib01 7/3/2008 1,986.3 0.000 0 7.55 610.0 HABtrib01 9/17/2008 2,419.6 0.041 0 7.55 585.0

HABtrib02 7/3/2008 >2,419.6 0.000 0 7.48 798.0

HABtrib03 7/3/2008 2,419.6 0.000 0 7.67 628.0 HABtrib03 9/17/2008 1,986.3 0.025 0 7.45 602.0

HABtrib04 7/3/2008 1,119.9 0.000 0 7.52 635.0

HABtrib06 7/30/2008 410.6 0.000 0 7.66 613.0

HABtrib07 7/30/2008 344.8 0.000 0 7.59 628.0 HABtrib07 9/17/2008 394.5 0.018 0 7.14 489.0

HABtrib08 7/30/2008 435.2 0.000 0 7.42 619.0

HABtrib09 7/30/2008 727.0 0.000 0 7.35 623.0

HABtrib10 7/30/2008 920.8 0.000 0 6.99 615.0

HABtrib11 8/25/2008 NS 0.196 0 7.16 590.0

HABtrib12 8/25/2008 NS 0.005 0 7.10 605.0 HABtrib12 9/2/2008 >2,419.6 0.102 0 7.09 601.0 HABtrib12 9/17/2008 1,732.9 0.024 0 7.18 655.0

HABtrib13 9/4/2008 866.4 0.044 0 7.21 687.0

HABtrib14 9/4/2008 307.6 0.065 0 7.45 687.0 HABtrib14 9/17/2008 648.8 0.028 0 7.26 602.0

HABtrib2 6/17/2008 307.6 0.036 0 7.04 356.0

HABtrib3 6/17/2008 866.4 0.056 0 7.02 326.0 HABtrib3 7/3/2008 178.5 0.000 0 7.45 358.2

HABtribout 7/30/2008 816.4 0.011 0 7.33 601.0

HABtribout02 8/25/2008 NS 0.043 0 7.68 1622.0 HABtribout02 9/2/2008 5.2 0.000 0 7.76 1346.0


Figure 3: Easternmost SSO, Endean Park in Norwood.

Figure 4: Middle “Weighted” SSO, Endean Park in Norwood.


Figure 5: Close-up of sewer manhole, Endean Park in Norwood.

Figure 6: Third, Westernmost SSO at Endean Park in Norwood.


Plantingfield Brook Results Plantingfield Brook originates in Westwood, MA, and terminates west of Route 1 in Norwood, MA, where it joins Purgatory Brook (Figure 7). Plantingfield Brook is currently not part of the CWMN sampling program so there was no data indicating problems in Plantingfield Brook prior to follow-up sampling conducted in 2008. Due to the fact that Plantingfield Brook does discharge to Purgatory Brook and that Purgatory Brook has shown show repeated problems with bacteria, Plantingfield Brook was chosen to be part of the 2008 Follow-up Program. Physical access to Plantingfield brook is difficult and a substantial stretch of stream upstream of the sampling stations was not accessed. Instream samples were collected at three stations located in Norwood and all were well above the bacteria standard and several samples showed ammonia and/or surfactants in the stream as well. The stream was also accessed at one location in Westwood where it was found to have no flow. Further investigation led to the discovery of one particular outfall that appears to be discharging water polluted with sewage. Data for PFBout02 located in the Town of Norwood (Table 3) showed not only elevated levels of bacteria but high ammonia and surfactants as well. Flow was also found during dry weather at outfall PFBout01 but no pollution was indicated. PFBout02 is clearly contributing to the problems on Plantingfield Brook, but it is unclear whether it is the sole source of the problem. No instream samples were collected upstream of PFBout02. Further investigations upstream of PFB003 are still needed, perhaps during winter or early spring when vegetation is less dense. The town should investigate and remediate the problem at PFBout02.


Figure 7: Sampling Locations along Plantingfield Brook in Norwood, MA, 2008


Table 3: Data collected from Plantingfield Brook in Westwood and Norwood, MA, 2008.

Sample ID Date E.coli (MPN/100mL)

Ammonia (mg/L)

Surfactants (mg/L)


PFB001 9/2/2008 2,419.6 0.012 0.00 7.51 809 PFB001 9/16/2008 2,419.6 0.044 0.00 7.59 506 PFB001 9/25/2008 no sample 0.043 0.00 7.55 608 PFB001 10/17/2008 1,299.7 0.022 0.00 7.43 455

PFB002 9/16/2008 >2,419.6 0.043 0.00 7.79 485

PFB003 9/16/2008 2,419.6 0.052 0.25 7.67 487 PFB003 9/25/2008 no sample 0.062 0.00 7.32 585 PFB003 10/17/2008 1,203.3 0.028 0.00 7.55 489

PFBout01 9/16/2008 30.1 0.004 0.25 7.73 587 PFBout01 9/25/2008 no sample 0.000 0.00 7.83 388 PFBout01 10/17/2008 8.4 0.000 0.00 7.94 502

PFBout02 9/16/2008 12,997.0 0.202 0.50 7.62 535 PFBout02 9/25/2008 no sample 0.186 0.25 7.22 602 PFBout02 10/17/2008 6,131.0 0.204 0.25 7.31 585


Purgatory Brook Results Purgatory Brook is also located in the Towns of Westwood and Norwood, MA (Figure 8). Sampling in Purgatory Brook began near Route 1 in Norwood, MA, and continued upstream to PUR104 in Westwood. Instream samples PUR101, 102 and 106, all located in Norwood, exhibited significant bacterial contamination, along with measureable levels of ammonia and surfactants in the stream (Table 4). Stations PUR104, and 105 located in Westwood showed no pollution indicators. Station PUR103 in Westwood showed slightly elevated levels of bacteria and one low level detection of ammonia. Note that stations PURout01Stream and PURout02Stream were both instream stations, located just upstream of their associated outfalls. The reach immediately upstream from Route 1 in Norwood had several outfalls not listed on town drainage maps. These outfalls were made of PVC pipe and appear to have been installed by abutters. One outfall (PURout03) did discharge during one sampling round but was dry during subsequent investigation. The discharge that was sampled at this outfall did not have significant pollutants associated with it. Site PURout01 was the only outfall with dry weather flow that exhibited high levels of bacteria. However, bacteria levels were higher in the stream immediately above of the outfall. Though the discharge from outfall PURout01 appears to be contributing to the pollutant load in Purgatory Brook there are likely other sources further upstream. The data suggest that an additional, undiscovered source of sewage pollution likely exists somewhere between PUR106 and PURout02Stream. Town of Norwood drainage maps indicate the existence of an outfall in this reach, somewhat downstream of PUR106, but we were unable to access the outfall because of the density of the vegetation. The Town of Norwood should undertake further investigations in the drainage system associated with PURout01 and the outfall reportedly located near PUR106. Additional sampling between PUR 106 and PUR104 in the Town of Westwood should also be considered in response to the lower levels of bacteria found at PUR103.


Figure 8: Sampling locations along Purgatory Brook in Norwood and Westwood, MA, 2008


Table 4: Data collected from Purgatory Brook in Westwood and Norwood, MA, 2008.

Sample ID Date E.coli

(MPN/100mL) Ammonia

(mg/L) Surfactants

(mg/L) pH Conductivity

(µs) PUR101 7/10/2008 2,419.6 0.023 0.25 7.30 1375 PUR101 8/6/2008 343.6 0.012 0.00 7.66 866

PUR102 7/10/2008 1,732.9 0.028 0.25 7.23 1362 PUR102 8/6/2008 490.7 0.034 0.00 7.57 901

PUR103 8/6/2008 177.2 0.011 0.00 7.62 878 PUR103 9/2/2008 290.9 0.000 0.00 7.60 522

PUR104 8/6/2008 71.8 0.000 0.00 7.33 742 PUR104 9/2/2008 34.1 0.000 0.00 7.38 509

PUR105 8/6/2008 110.8 0.000 0.00 7.82 657 PUR105 9/2/2008 84.2 0.000 0.00 7.39 513

PUR106 8/6/2008 299.8 0.018 0.00 7.44 801 PUR106 9/2/2008 307.6 0.011 0.00 7.22 1622

PURout01 7/10/2008 1,413.6 0.092 0.25 6.95 1220 PURout01 9/15/2008 648.8 0.022 0.00 7.46 755

PURout01Stream 7/10/2008 1,553.1 0.022 0.25 7.26 1349 PURout01Stream 9/15/2008 866.4 0.036 0.00 7.35 920

PURout02 7/10/2008 101.4 0.045 0.25 6.94 649 PURout02 9/15/2008 55.4 0.062 0.00 7.47 857

PURout02Stream 7/10/2008 1,299.7 0.068 0.25 7.24 1375 PURout02Stream 9/15/2008 1,046.2 0.032 0.00 7.42 1041

PURout03 7/10/2008 8.5 0.012 0.00 6.93 650


Neponset River Results CWMN data for the Lower Neponset River indicate relatively good water quality as the river exits Fowl Meadow near Neponset Valley Parkway, followed by steady and increasingly severe deterioration during dry weather as you move downstream to Lower Mills. The CWMN data are corroborated by MWRA data for the Neponset Estuary beginning at Lower Mills which indicate that the Lower Neponset now experiences worse bacterial water quality than the Lower Charles or the Lower Mystic, and that while conditions on the Charles have improved dramatically, and conditions on the Mystic improved somewhat, conditions on the Lower Neponset have been slowly deteriorating. Sampling along the lower portion of the Neponset River was conducted in two separate reaches. The first reach starts at Paul’s Bridge and ends at the Tileston and Hollingsworth Dam (Figure 9). This was the same stretch that was monitored in 2007. The second stretch of river is between the Tileston and Hollingsworth Dam and the Baker Dam downstream. This second reach has higher ambient bacteria counts than the first reach and had not previously been sampled as part of the Association Follow-up Program. In the first stretch of river, the 2007 Follow-up Program identified five, Boston Water and Sewer Commission (BWSC) owned, outfalls with clear indications of illicit connections (6GSDO110, 5FSDO116, 5FSDO117, 4FSDO204, 5GSDO162). One additional BWSC outfall (2FSDO120) was found to have dry weather flow but lacked pollution indicators. In addition, one Department of Conservation and Recreation (DCR) owned outfall (3FSDO160)(which includes a collection area partially owned by BWSC) where less decisive indicators were found. During late 2007 and early 2008 BWSC initiated a number of efforts to further investigate or remediate its four outfalls. During the 2008 survey, one of the BWSC outfalls that had been identified as a problem in 2007 (5FSDO116) did not have flow during dry weather and appears to have been fully corrected. Contact with the BWSC revealed that an unknown lateral had been located in the drain system and capped. A second outfall (6GSDO110) was not sampled in 2008 because the outfall was inundated with river water and no distinction could be made between the river and possible discharge. Note that this outfall (6GSDO110) is not plotted on the map because it was not sampled. All the other BWSC outfalls that were found to be problems during 2007 (5FSDO117, 4FSDO204, 5GSDO162) were found to still have sewage indicators in 2008. Furthermore BWSC outfall 2FSDO120 which was flowing but clean during 2007, turned out to be flowing with mild sewage indicators during 2008. Outfall 3FSDO160 which is owned by DCR but numbered in the BWSC GIS system, also had consistent flows in dry weather during both sampling years. During 2008, this outfall exhibited consistently poor water quality for all indicators. Note that while this outfall is owned by DCR, much of the tributary collection system is managed by BWSC. Sampling along the second, more downstream, stretch (between the two dams) identified three “new” BWSC owned outfalls with heavy flow during dry weather. All three of these outfalls


(6GSDO108, 7HSDO105, and 7HSDO285) exhibited extremely high bacteria counts. In addition to the high bacteria levels, all three outfalls also exhibited high ammonia and surfactant levels. None of the other outfalls in this reach (generally owned by BWSC or DCR and including collection areas owned by the Town of Milton) were flowing during dry weather. Table 5 below summarizes the status of the various outfalls found to be flowing during dry weather along the Lower Neponset River. It would appear that the eight BWSC outfalls which currently have or may still have illicit connection indicators and the one DCR outfall which has illicit connection indicators, (6GSDO110, 5FSDO117, 4FSDO204, 2FSDO120, 3FSDO160, 3FSDO162, 6GSDO108, 7HSDO105, and 7HSDO285) collectively represent the primary source of poor dry weather bacterial water quality observed at Lower Mills. This seems particularly likely given the very high concentrations and larger discharge volumes associated with the three “newly” identified outfalls on the downstream reach of the Lower Neponset. DCR should initiate further investigation of the sources of pollution impacting outfall 3FSDO160. The BWSC should continue and accelerate, its ongoing efforts to investigate and remediate illicit connections in these drainage areas.

Table 5: Summary of Lower Neponset outfalls sampled in 2007 and 2008 showing the presence or absence of sewage

pollution indicators and current status.

BWSC ID NepRWA

ID 2007 Results 2008 Results

Current Status 6GSDO110 SDO110 Present Not Sampled Unknown 5FSDO116 SDO116 Present No Flow Resolved 5FSDO117 SDO117 Present Present Problem 2FSDO120 SDO120 Absent Present Problem 3FSDO160* SDO160 Present Present Problem 3FSDO162 SDO162 Present Present Problem 5GSDO171 SDO171 Not Sampled Absent Resolved 4FSDO204 SDO204 Present Present Problem 7HSDO105 SDO105 Not Sampled Present Problem 6GSDO108 SDO108 Not Sampled Present Problem 7HSDO285 SDO285 Not Sampled Present Problem

* indicates DCR owned outfall


Figure 9: Sampling locations along the lower main stem of the Neponset River in Milton and Boston, MA, 2008. All outfalls are located in Boston.


Table 6: Data collected from outfalls along the lower Neponset River, 2008.

BWSC ID NepRWA ID

Date E.coli (MPN/100mL)

Ammonia (mg/L)

Surfactants (mg/L)


7HSDO105 SDO105 8/27/2008 4,884 2.464 1.5 7.34 945 7HSDO105 SDO105 9/11/2008 77,010 2.223 1.5 7.64 631

6GSDO108 SDO108 8/27/2008 >241,960 >3.0 1.5 7.43 611 6GSDO108 SDO108 9/11/2008 1,480 >3.0 0.75 7.61 676

5FSDO117 SDO117 8/5/2008 3,448 0.034 0.25 7.35 1345 5FSDO117 SDO117 9/3/2008 >24,196 0.082 0 7.49 1595

2FSDO120 SDO120 8/5/2008 216 0.026 0.25 7.08 1865 2FSDO120 SDO120 9/3/2008 186 0.025 0 6.91 2402

3FSDO159 SDO159 8/5/2008 0 0.173 0 8.4 186.6 3FSDO159 SDO159 9/3/2008 0 0.083 0 8.45 206.3

3FSDO160 SDO160 8/5/2008 15,531 0.498 0.25 7.21 1956 3FSDO160 SDO160 9/3/2008 1,723 0.386 0.25 7.6 2215

3FSDO162 SDO162 8/5/2008 0 2.51 0.25 7.53 965 3FSDO162 SDO162 9/3/2008 >24,196 1.861 0.25 7.84 993

5GSDO171 SDO171 9/3/2008 41 0.018 0 7.87 1013

4FSDO204 SDO204 8/5/2008 1,553,100 2.306 >3.0 6.87 550 4FSDO204 SDO204 9/3/2008 >24196 2.252 >3.0 7.12 699

7HSDO285 SDO285 8/27/2008 51,720 2.21 >3.0 7.61 1136 7HSDO285 SDO285 9/11/2008 41,060 2.155 >3.0 7.45 1088


Appendix A: Data Quality Objectives and QC Tables for E.coli, Ammonia, and Surfactant data.

Data Quality Objectives

Analyte Units Expected Range Action Thresholds MDL Resolution Accuracy Precision

E. coli (Colilert) MPN cfu/100 mL 0-2420, extended

w/dilutions 235 1

MPN/100 ml

depends on dilution

>2420 on positive and 0 on negative

30% RPD for log 10 transformed data

Ammonia Reported by lab in uM, converted to

mg/L 0.005 - 0.5 mg/L 0.2-2.0 mg/L 0.005

mg/L n/a 85% to 115%

25% RPD for values>0.5 mg/L and

50% RPD for values<0.5 mg/L

Surfactants mg/L 0-3 0.25 0.125 0.125 +/- 10% @ 2.25

mg/L; +/- 20% @ 0.75 mg/L

+/- 0.125 mg/L

QC data for E.coli analyses.

Date Original Log Duplicate Log RPD (%) Result Blank Result Positive Result Negative Result 6/17/2008 2143.0 3.33 2755.0 3.44 3.22 PASS 0 PASS >2419.6 PASS 0 PASS 7/3/2008 178.5 2.25 235.9 2.37 5.24 PASS 0 PASS >2419.6 PASS 0 PASS 7/10/2008 108.0 2.03 101.4 2.01 1.36 PASS 0 PASS >2419.6 PASS 0 PASS 7/30/2008 920.8 2.96 980.4 2.99 0.91 PASS 0 PASS >2419.6 PASS 0 PASS 8/5/2008 3448.0 3.54 3873.0 3.59 1.42 PASS 0 PASS >2419.6 PASS 0 PASS 8/6/2008 307.6 2.49 248.1 2.39 3.82 PASS 0 PASS >2419.6 PASS 0 PASS 8/20/2008 6.3 0.80 10.8 1.03 25.54 PASS 0 PASS >2419.6 PASS 0 PASS 8/27/2008 3450.0 3.54 4884.0 3.69 4.18 PASS 0 PASS >2419.6 PASS 0 PASS 9/2/2008 307.6 2.49 313.0 2.50 0.30 PASS 0 PASS >2419.6 PASS 0 PASS 9/3/2008 186.0 2.27 184.2 2.27 0.19 PASS 0 PASS >2419.6 PASS 0 PASS 9/4/2008 866.4 2.94 920.8 2.96 0.90 PASS 0 PASS >2419.6 PASS 0 PASS 9/11/2008 1480.0 3.17 2330.0 3.37 6.03 PASS 0 PASS >2419.6 PASS 0 PASS 9/15/2008 55.4 1.74 64.5 1.81 3.72 PASS 0 PASS >2419.6 PASS 0 PASS 9/16/2008 41.0 1.61 30.1 1.48 8.68 PASS 0 PASS >2419.6 PASS 0 PASS 9/17/2008 125.9 2.10 131.7 2.12 0.93 PASS 0 PASS >2419.6 PASS 0 PASS 10/17/2008 1203.3 3.08 658.6 2.82 8.87 PASS 0 PASS >2419.6 PASS 0 PASS


QC data for Ammonia analyses

Date Original Duplicate RPD (%)

Result Blank Result

6/17/2008 0.049 0.033 39.02 PASS ND PASS 7/3/2008 0 0 0.00 PASS ND PASS 7/10/2008 0.092 0.099 7.33 PASS ND PASS 7/30/2008 0 0 0.00 PASS ND PASS 8/5/2008 0.173 0.166 4.13 PASS ND PASS 8/6/2008 0 0 0.00 PASS ND PASS 8/20/2008 0 0 0.00 PASS ND PASS 8/27/2008 2.464 2.221 10.37 PASS ND PASS 9/2/2008 0 0 0.00 PASS ND PASS 9/3/2008 0.083 0.112 29.74 PASS ND PASS 9/4/2008 0.044 0.056 24.00 PASS ND PASS 9/11/2008 2.223 2.188 1.59 PASS ND PASS 9/15/2008 0.032 0.052 47.62 PASS ND PASS 9/16/2008 0.125 0.108 14.59 PASS ND PASS 9/17/2008 0 0 0.00 PASS ND PASS 10/17/2008 0 0 0.00 PASS ND PASS 8/25/2008 0.196 0.177 10.19 PASS ND PASS 9/25/2008 0.062 0.055 11.97 PASS ND PASS

QC data for Surfactant analyses.

Date Original Duplicate RPD (%)

Result Blank Result

6/17/2008 0 0 0.00 PASS 0 PASS 7/3/2008 0 0 0.00 PASS 0 PASS 7/10/2008 0.25 0.25 0.00 PASS 0 PASS 7/30/2008 0 0 0.00 PASS 0 PASS 8/5/2008 0 0 0.00 PASS 0 PASS 8/6/2008 0 0 0.00 PASS 0 PASS 8/20/2008 0 0 0.00 PASS 0 PASS 8/27/2008 1.5 1.5 0.00 PASS 0 PASS 9/2/2008 0 0 0.00 PASS 0 PASS 9/3/2008 0 0 0.00 PASS 0 PASS 9/4/2008 0 0 0.00 PASS 0 PASS 9/11/2008 1.5 1.5 0.00 PASS 0 PASS 9/15/2008 0 0 0.00 PASS 0 PASS 9/16/2008 0.25 0.25 0.00 PASS 0 PASS 9/17/2008 0 0 0.00 PASS 0 PASS 10/17/2008 0 0 0.00 PASS 0 PASS 8/25/2008 0 0 0.00 PASS 0 PASS 9/25/2008 0 0 0.00 PASS 0 PASS

2008 “follow-up” sampling program final report

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