This report presents the methodology and results for a study of surface-water quality of the Lycoming Creek watershed in north-central Pennsylvania during August 1–3, 2011. The study was done in cooperation with the Williamsport Municipal Water Authority and the Pennsylvania Department of Environmental Protection. Samples of stream water were collected from 31 sites in an area of exploration and production of natural gas from the Marcellus Shale – 5 sites on the main stem of Lycoming Creek and 26 sites on tributary streams. The samples provide a snapshot of the base-flow water-quality conditions, which helps document the spatial variability in water-quality and could be useful for assessing future changes.
The 272-square mile Lycoming Creek watershed is located within Lycoming, Tioga, and Sullivan Counties in north-central Pennsylvania. Lycoming Creek flows 37.5 miles to its confluence with the West Branch Susquehanna River in the city of Williamsport. A well field that supplies water for Williamsport captures some water that has infiltrated the streambed of Lycoming Creek. Because the stream provides a source of water to the well field, this study focused on the stream-water quality as it relates to drinking-water standards as opposed to aquatic life.
Surface-water samples collected at 20 sites by the U.S. Geological Survey and 11 sites by the Pennsylvania Department of Environmental Protection were analyzed by each agency for a suite of constituents that included major ions, trace metals, nutrients, and radiochemicals. None of the analytical results failed to meet standards set by the U.S. Environmental Protection Agency as maximum contaminant levels for drinking water.
Results of the sampling show the substantial spatial variability in base-flow water quality within the Lycoming Creek watershed caused by the interrelated effects of physiography, geology and land use. Dissolved-solids concentrations ranged from less than the laboratory reporting level of 12 milligrams per liter (mg/L) in Wolf Run, a pristine forested watershed, to 202 mg/L in Bottle Run, a watershed with more development near Williamsport. Concentrations of the major ions ranged over at least one order of magnitude; chloride had the largest range from 0.3 to 45.4 mg/L, with nine samples exceeding the natural background level of about 5 mg/L, most likely because of the application of deicing salt to roads. Trace constituents were even more variable, with concentrations for aluminum, cobalt, and manganese ranging over almost four orders of magnitude. Samples from Red Run and Dutchman Run, watersheds that experienced past coal mining activity, had concentrations of 11 metals that were significantly greater than in samples collected from other streams. Samples from Bottle Run, the tributary of Lycoming Creek nearest to Williamsport, contained elevated levels of chloride and boron, constituents associated with urban development.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20175154","collaboration":"Prepared in cooperation with the Williamsport Municipal Water Authority","usgsCitation":"Risser, D.W., and Conlon, M.D., 2018, Surface-water quality in the Lycoming Creek watershed, north-central Pennsylvania, August 1–3, 2011: U.S. Geological Survey Scientific Investigations Report 2017–5154, 77 p., https://doi.org/10.3133/sir20175154.","productDescription":"ix, 77 p.","numberOfPages":"91","onlineOnly":"Y","additionalOnlineFiles":"N","ipdsId":"IP-043927","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":354219,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2017/5154/sir20175154.pdf","text":"Report","size":"8.23 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2017-5154"},{"id":354218,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2017/5154/coverthb.jpg"}],"country":"United States","state":"Pennsylvania","otherGeospatial":"Lycoming Creek Watershed","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -77.1667,\n 41.2\n ],\n [\n -76.6667,\n 41.2\n ],\n [\n -76.6667,\n 41.6667\n ],\n [\n -77.1667,\n 41.6667\n ],\n [\n -77.1667,\n 41.2\n ]\n ]\n ]\n }\n }\n ]\n}","contact":"Director, Pennsylvania Water Science Center
U.S. Geological Survey
215 Limekiln Road
New Cumberland, PA. 17070
The Devonian-age Marcellus Shale and the Ordovician-age Utica Shale, which have the potential for natural gas development, underlie Pike County and neighboring counties in northeastern Pennsylvania. In 2015, the U.S. Geological Survey, in cooperation with the Pike County Conservation District, conducted a study that expanded on a previous more limited 2012 study to assess baseline shallow groundwater quality in bedrock aquifers in Pike County prior to possible extensive shale-gas development. Seventy-nine water wells ranging in depths from 80 to 610 feet were sampled during June through September 2015 to provide data on the presence of methane and other aspects of existing groundwater quality in the various bedrock geologic units throughout the county, including concentrations of inorganic constituents commonly present at low values in shallow, fresh groundwater but elevated in brines associated with fluids extracted from geologic formations during shale-gas development. All groundwater samples collected in 2015 were analyzed for bacteria, dissolved and total major ions, nutrients, selected dissolved and total inorganic trace constituents (including metals and other elements), radon-222, gross alpha- and gross beta-particle activity, dissolved gases (methane, ethane, and propane), and, if sufficient methane was present, the isotopic composition of methane. Additionally, samples from 20 wells distributed throughout the county were analyzed for selected man-made volatile organic compounds, and samples from 13 wells where waters had detectable gross alpha activity were analyzed for radium-226 on the basis of relatively elevated gross alpha-particle activity.
Results of the 2015 study show that groundwater quality generally met most drinking-water standards for constituents and properties included in analyses, but groundwater samples from some wells had one or more constituents or properties, including arsenic, iron, manganese, pH, bacteria, sodium, chloride, sulfate, total dissolved solids, and radon-222, that did not meet (commonly termed failed or exceeded) primary or secondary maximum contaminant levels (MCLs) or Health Advisories (HA) for drinking water. Except for iron, dissolved and total concentrations of major ions and most trace constituents generally were similar. Only 1 of 79 well-water samples had any constituent that exceeded a MCL, with an arsenic concentration of about 30 micrograms per liter (µg/L) that was higher than the MCL of 10 µg/L. However, total arsenic concentrations were higher than the HA of 2 µg/L in samples from another 12 of 79 wells (about 15 percent). Secondary maximum contaminant levels (SMCLs) were exceeded most frequently by pH and concentrations of iron and manganese. The pH was outside of the SMCL range of 6.5–8.5 in samples from 24 of 79 wells (30 percent), ranging from 5.5 to 9.2; more samples had pH values less than 6.5 than had pH values greater than 8.5. Total iron concentrations typically were much greater than dissolved iron concentrations, indicating substantial presence of iron in particulate phase, and exceeded the SMCL of 300 µg/L more often [35 of 79 samples (44 percent)] than dissolved iron concentrations [samples from 8 of 79 wells (10 percent)]. Total manganese concentrations exceeded the SMCL of 50 µg/L in samples from 31 of 79 wells (39 percent) and the HA of 300 µg/L in samples from 13 of 79 wells (about 16 percent). A few (1–2) samples had concentrations of sodium, chloride, sulfate, or TDS higher than the SMCLs of 60, 250, 250, and 500 mg/L, respectively. However, dissolved sodium concentrations were higher than the HA of 20 mg/L in samples from 15 of 79 wells (nearly 20 percent). Total coliform bacteria were detected in samples from 25 of 79 wells (32 percent) but Escherichia coli were not detected in any sample. Radon-222 activities ranged from 11 to 5,100 picocuries per liter (pCi/L), with a median of 1,440 pCi/L, and exceeded the proposed and the alternate proposed drinking-water standards of 300 and 4,000 pCi/L, respectively, in samples from 60 of 79 wells (75 percent) and in samples from 2 of 79 wells (3 percent), respectively.
Groundwater samples from all wells were analyzed for dissolved methane by one contract laboratory that determined water from 19 of the 79 wells (24 percent) had concentrations of methane greater than the reporting level of 0.010 milligrams per liter (mg/L) with a maximum methane concentration of 2.5 mg/L. Methane concentrations in 18 replicate samples submitted to a second laboratory for dissolved gas and isotopic analysis generally were higher by as much as a factor of 2.7 from those determined by the first laboratory, indicating potential bias related to combined sampling and analytical methods, and therefore, caution needs to be used when comparing methane results determined by different methods. The isotopic composition of methane in 9 of 10 samples with sufficient dissolved methane (about 0.3 mg/L) for isotopic analysis is consistent with values reported for methane of microbial origin produced through carbon dioxide reduction; an isotopic shift in 1 or 2 samples may indicate subsequent methane oxidation. The low concentrations of ethane relative to methane in these samples further indicate that the methane may be of microbial origin. Groundwater samples with relatively elevated methane concentrations (near or greater than 0.3 mg/L) also had chemical compositions that differed in some respects from groundwater with relatively low methane concentrations (less than 0.3 mg/L) by having higher pH (greater than 8) and higher concentrations of sodium, lithium, boron, fluoride, arsenic, and bromide and chloride/bromide ratios indicative of mixing with a small amount of brine of probable natural occurrence.
The spatial distribution of groundwater compositions differs by topographic setting and lithology and generally shows that (1) relatively dilute, slightly acidic, oxygenated, calcium-carbonate type waters tend to occur in the uplands underlain by the undivided Poplar Gap and Packerton members of the Catskill Formation in southwestern Pike County; (2) waters of near neutral pH with the highest amounts of hardness (calcium and magnesium) generally occur in areas of intermediate altitudes underlain by other members of the Catskill Formation; and (3) waters with pH values greater than 8, low oxygen concentrations, and the highest arsenic, sodium, lithium, bromide, and methane concentrations can be present in deep wells in uplands but most frequently occur in stream valleys, especially at low altitudes (less than about 1,200 feet above North American Vertical Datum of 1988) where groundwater may be discharging regionally, such as to the Delaware River in northern and eastern Pike County. Thus, the baseline assessment of groundwater quality in Pike County prior to gas-well development shows that shallow (less than about 1,000 feet deep) groundwater generally meets primary drinking-water standards for inorganic constituents but varies spatially, with methane and some constituents present in high concentrations in brine (and connate waters from gas and oil reservoirs) present at low to moderate concentrations in some parts of Pike County.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20175110","collaboration":"Prepared in cooperation with the Pike County Conservation District","usgsCitation":"Senior, L.A., and Cravotta, C.A., III, 2017: Baseline assessment of groundwater quality in Pike County, Pennsylvania, 2015: U.S. Geological Survey Scientific Investigations Report 2017–5110, 181 p., https://doi.org/10.3133/sir20175110.","productDescription":"Report: xii, 181 p.; Data Release","onlineOnly":"Y","additionalOnlineFiles":"N","ipdsId":"IP-088156","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":350196,"rank":3,"type":{"id":30,"text":"Data Release"},"url":"https://www.sciencebase.gov/catalog/item/5980c3c0e4b0a38ca278a8c9","text":"USGS Data Release - ","linkHelpText":"Field properties and results of laboratory analysis of groundwater samples collected from 79 wells in Pike County, Pennsylvania, 1982-2015"},{"id":350194,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2017/5110/coverthb.jpg"},{"id":350195,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2017/5110/sir20175110.pdf","text":"Report","size":"7.58 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2017-5110"}],"country":"United States","state":"Pennsylvania","county":"Pike County","geographicExtents":"{\"type\":\"FeatureCollection\",\"features\":[{\"type\":\"Feature\",\"geometry\":{\"type\":\"Polygon\",\"coordinates\":[[[-74.7506,41.4274],[-74.7487,41.4287],[-74.7461,41.4303],[-74.7438,41.4305],[-74.7408,41.4298],[-74.7389,41.4286],[-74.7376,41.4261],[-74.7384,41.4229],[-74.7391,41.4197],[-74.7405,41.4166],[-74.7412,41.4145],[-74.7415,41.4123],[-74.7419,41.4103],[-74.7421,41.4094],[-74.7409,41.4066],[-74.7392,41.4025],[-74.7376,41.4003],[-74.7349,41.3987],[-74.732,41.3973],[-74.7278,41.3963],[-74.7247,41.3958],[-74.7205,41.3947],[-74.7175,41.3929],[-74.7154,41.3917],[-74.7137,41.389],[-74.7126,41.3866],[-74.7105,41.3842],[-74.7064,41.3803],[-74.7011,41.3753],[-74.6985,41.373],[-74.6962,41.3713],[-74.6938,41.3688],[-74.6934,41.3683],[-74.6912,41.3662],[-74.69,41.3639],[-74.6901,41.3621],[-74.6913,41.3598],[-74.6955,41.3576],[-74.7019,41.3549],[-74.7052,41.3536],[-74.7062,41.3532],[-74.7113,41.3519],[-74.7161,41.3502],[-74.7211,41.3485],[-74.7247,41.3473],[-74.7278,41.3469],[-74.7322,41.3469],[-74.7364,41.3475],[-74.7396,41.3473],[-74.742,41.3471],[-74.7461,41.3464],[-74.7506,41.3455],[-74.7537,41.3442],[-74.7571,41.3422],[-74.7581,41.3411],[-74.7602,41.3391],[-74.7619,41.3362],[-74.7633,41.3331],[-74.7651,41.33],[-74.767,41.3283],[-74.7697,41.3269],[-74.773,41.3259],[-74.7754,41.3253],[-74.7764,41.325],[-74.7802,41.3243],[-74.7846,41.3244],[-74.787,41.324],[-74.79,41.3237],[-74.7925,41.3228],[-74.7937,41.3219],[-74.7949,41.3207],[-74.795,41.3186],[-74.7944,41.3172],[-74.7931,41.3159],[-74.7925,41.3145],[-74.7925,41.3127],[-74.7932,41.3117],[-74.7937,41.3109],[-74.7945,41.3103],[-74.796,41.3088],[-74.8017,41.3063],[-74.8077,41.3027],[-74.8126,41.2999],[-74.8163,41.2976],[-74.8193,41.2958],[-74.8218,41.2946],[-74.8223,41.2943],[-74.8254,41.2922],[-74.828,41.29],[-74.8299,41.2877],[-74.8319,41.2851],[-74.8338,41.2823],[-74.8358,41.2799],[-74.8376,41.2779],[-74.8389,41.2752],[-74.8392,41.2729],[-74.8402,41.2709],[-74.8418,41.269],[-74.843,41.2658],[-74.8436,41.2631],[-74.8442,41.2604],[-74.8442,41.2594],[-74.8461,41.2559],[-74.8497,41.2531],[-74.852,41.2523],[-74.8551,41.2506],[-74.8571,41.2483],[-74.8594,41.2459],[-74.86,41.244],[-74.8612,41.2417],[-74.8618,41.239],[-74.8629,41.237],[-74.8661,41.2335],[-74.8662,41.2322],[-74.8657,41.2294],[-74.8636,41.2272],[-74.8612,41.2249],[-74.8605,41.224],[-74.8599,41.2233],[-74.8593,41.2216],[-74.8598,41.2193],[-74.8613,41.2162],[-74.8621,41.2149],[-74.8629,41.214],[-74.8648,41.2118],[-74.8672,41.2086],[-74.8688,41.2062],[-74.8714,41.2022],[-74.8744,41.1977],[-74.8775,41.1931],[-74.8788,41.1904],[-74.8799,41.1881],[-74.8805,41.1861],[-74.8814,41.1844],[-74.8829,41.1819],[-74.8834,41.1812],[-74.8853,41.179],[-74.8884,41.1758],[-74.8916,41.1741],[-74.8935,41.1729],[-74.8957,41.1713],[-74.8972,41.1697],[-74.8985,41.1675],[-74.8999,41.1658],[-74.9017,41.1626],[-74.905,41.1568],[-74.9084,41.1526],[-74.9108,41.15],[-74.915,41.1458],[-74.9196,41.1416],[-74.9242,41.139],[-74.9302,41.1353],[-74.9346,41.1333],[-74.9381,41.1317],[-74.9406,41.1312],[-74.943,41.1303],[-74.9442,41.1294],[-74.9465,41.1277],[-74.9471,41.1258],[-74.9485,41.1244],[-74.9495,41.1231],[-74.9521,41.1216],[-74.9556,41.1197],[-74.9564,41.1192],[-74.9594,41.118],[-74.9624,41.1157],[-74.9652,41.1144],[-74.9667,41.114],[-74.9697,41.1138],[-74.9716,41.1136],[-74.9728,41.1136],[-74.9758,41.112],[-74.9771,41.1114],[-74.9775,41.111],[-74.9807,41.1084],[-74.9837,41.1056],[-74.9867,41.1002],[-74.9886,41.097],[-74.989,41.0962],[-74.9909,41.0935],[-74.9915,41.0926],[-74.9921,41.0931],[-74.9927,41.0931],[-74.9933,41.0936],[-74.9939,41.094],[-74.9952,41.0936],[-74.9958,41.0936],[-74.9964,41.0927],[-74.9983,41.0914],[-74.9995,41.091],[-75.0025,41.0924],[-75.0105,41.0898],[-75.0137,41.0858],[-75.0192,41.0864],[-75.0223,41.0851],[-75.0242,41.0824],[-75.0267,41.082],[-75.0302,41.0848],[-75.032,41.0871],[-75.0338,41.0889],[-75.0343,41.0894],[-75.0356,41.0899],[-75.0373,41.0908],[-75.0449,41.1005],[-75.0467,41.1032],[-75.0618,41.123],[-75.0653,41.1276],[-75.0712,41.1346],[-75.0764,41.1419],[-75.0934,41.1445],[-75.1147,41.1467],[-75.1251,41.1478],[-75.136,41.1489],[-75.1561,41.1516],[-75.1539,41.162],[-75.1518,41.1683],[-75.1463,41.1873],[-75.1442,41.1949],[-75.1429,41.1999],[-75.1373,41.2193],[-75.129,41.2478],[-75.1283,41.25],[-75.1276,41.2536],[-75.187,41.2506],[-75.2011,41.25],[-75.2335,41.2478],[-75.2476,41.2467],[-75.2654,41.2452],[-75.2918,41.242],[-75.2949,41.2412],[-75.2998,41.2408],[-75.3077,41.24],[-75.3273,41.2377],[-75.3285,41.2413],[-75.3301,41.2463],[-75.3319,41.2491],[-75.3366,41.2533],[-75.3414,41.2561],[-75.3426,41.257],[-75.3469,41.2589],[-75.3474,41.2598],[-75.3468,41.2611],[-75.3448,41.2652],[-75.3436,41.2665],[-75.3417,41.2669],[-75.3337,41.2695],[-75.3324,41.2704],[-75.3323,41.275],[-75.3322,41.2786],[-75.3309,41.2795],[-75.3297,41.2804],[-75.3296,41.2831],[-75.3296,41.284],[-75.3302,41.2849],[-75.3295,41.2863],[-75.3264,41.2876],[-75.3251,41.2889],[-75.3251,41.2898],[-75.3257,41.2912],[-75.3268,41.2935],[-75.328,41.2953],[-75.328,41.2971],[-75.3273,41.298],[-75.3261,41.2985],[-75.3248,41.2989],[-75.3236,41.2993],[-75.3224,41.2998],[-75.3217,41.3007],[-75.3211,41.3016],[-75.3198,41.3038],[-75.3185,41.3051],[-75.3173,41.3065],[-75.3166,41.3074],[-75.3141,41.311],[-75.3134,41.3132],[-75.3164,41.3165],[-75.3163,41.3174],[-75.3163,41.3187],[-75.3162,41.3196],[-75.3156,41.3201],[-75.3132,41.3209],[-75.3125,41.3209],[-75.3119,41.3218],[-75.3125,41.3223],[-75.3124,41.3241],[-75.3118,41.325],[-75.3105,41.3268],[-75.3105,41.3282],[-75.3117,41.3291],[-75.3188,41.3369],[-75.3194,41.3374],[-75.3206,41.3379],[-75.3261,41.3384],[-75.331,41.3362],[-75.3323,41.3362],[-75.3341,41.3363],[-75.3359,41.3363],[-75.3378,41.3363],[-75.3432,41.3382],[-75.3431,41.3405],[-75.3388,41.3436],[-75.3369,41.3449],[-75.3374,41.3477],[-75.3386,41.3495],[-75.3385,41.3504],[-75.3391,41.3509],[-75.3416,41.3518],[-75.3421,41.3532],[-75.3427,41.355],[-75.3469,41.3578],[-75.3475,41.3587],[-75.3475,41.3596],[-75.3497,41.366],[-75.3509,41.3679],[-75.3483,41.371],[-75.3465,41.371],[-75.3453,41.371],[-75.3447,41.3709],[-75.344,41.3714],[-75.3428,41.3732],[-75.3415,41.3741],[-75.3409,41.3745],[-75.3396,41.3759],[-75.3384,41.3763],[-75.3372,41.3763],[-75.3365,41.3763],[-75.3353,41.3758],[-75.3347,41.3744],[-75.3342,41.3735],[-75.3336,41.3726],[-75.333,41.3721],[-75.3318,41.3712],[-75.3282,41.3689],[-75.3209,41.3678],[-75.3203,41.3678],[-75.3172,41.3682],[-75.3129,41.37],[-75.3116,41.3713],[-75.311,41.3722],[-75.3103,41.3735],[-75.3109,41.374],[-75.3121,41.3754],[-75.3114,41.3772],[-75.3077,41.3776],[-75.3048,41.3735],[-75.3036,41.3725],[-75.3018,41.3711],[-75.3012,41.3707],[-75.3,41.3702],[-75.2969,41.3701],[-75.2926,41.3705],[-75.2914,41.3709],[-75.2895,41.3718],[-75.2877,41.3722],[-75.2859,41.3722],[-75.2828,41.3726],[-75.2699,41.3738],[-75.2674,41.3737],[-75.2656,41.3741],[-75.2643,41.3755],[-75.2636,41.38],[-75.2635,41.3814],[-75.2635,41.3827],[-75.2622,41.3841],[-75.2603,41.3854],[-75.2579,41.3863],[-75.2554,41.3871],[-75.2541,41.388],[-75.2528,41.3903],[-75.2528,41.3916],[-75.2528,41.3925],[-75.2531,41.3998],[-75.2525,41.4011],[-75.2506,41.4029],[-75.2511,41.4075],[-75.2527,41.4139],[-75.2489,41.4161],[-75.2471,41.4169],[-75.2464,41.4183],[-75.2457,41.4219],[-75.2445,41.4214],[-75.2433,41.4214],[-75.2341,41.4208],[-75.2335,41.4208],[-75.2334,41.4217],[-75.2346,41.4226],[-75.2321,41.4253],[-75.2284,41.4261],[-75.2205,41.4251],[-75.2149,41.4268],[-75.2111,41.4299],[-75.2043,41.4321],[-75.2037,41.4325],[-75.1999,41.4352],[-75.1992,41.437],[-75.1986,41.4379],[-75.1979,41.4397],[-75.1912,41.44],[-75.1905,41.4423],[-75.1862,41.444],[-75.1861,41.4454],[-75.1867,41.4463],[-75.189,41.4491],[-75.189,41.45],[-75.189,41.4509],[-75.187,41.4545],[-75.1882,41.4558],[-75.1882,41.4572],[-75.1881,41.4581],[-75.1856,41.4599],[-75.1844,41.4603],[-75.1813,41.4616],[-75.1743,41.4688],[-75.1737,41.4697],[-75.1692,41.4755],[-75.1679,41.4768],[-75.1666,41.4781],[-75.1654,41.4799],[-75.1628,41.4835],[-75.1557,41.4925],[-75.1494,41.5001],[-75.1224,41.5341],[-75.0974,41.5663],[-75.0723,41.599],[-75.0699,41.602],[-75.068,41.5999],[-75.0645,41.5961],[-75.0613,41.5935],[-75.0582,41.5922],[-75.055,41.5906],[-75.0525,41.5877],[-75.0504,41.5857],[-75.0472,41.5821],[-75.0461,41.5805],[-75.043,41.5749],[-75.0408,41.571],[-75.0389,41.5699],[-75.0359,41.5671],[-75.0326,41.5657],[-75.0294,41.5636],[-75.0247,41.5598],[-75.0216,41.5563],[-75.0192,41.553],[-75.0176,41.5498],[-75.0168,41.5471],[-75.0174,41.5448],[-75.0189,41.5433],[-75.0198,41.5429],[-75.0215,41.5417],[-75.023,41.5403],[-75.0228,41.5377],[-75.0218,41.5353],[-75.02,41.5335],[-75.0176,41.5321],[-75.0133,41.5307],[-75.008,41.5278],[-75.0056,41.5255],[-75.0035,41.5229],[-75.0022,41.5202],[-75.0016,41.5182],[-75.0017,41.5157],[-75.0023,41.5146],[-75.0029,41.5125],[-75.0042,41.5105],[-75.003,41.5092],[-75.0025,41.5086],[-74.9994,41.5082],[-74.9963,41.5085],[-74.9926,41.5094],[-74.9889,41.5093],[-74.9866,41.5074],[-74.9844,41.5055],[-74.984,41.5029],[-74.984,41.5016],[-74.9838,41.5007],[-74.9846,41.497],[-74.9859,41.4911],[-74.9865,41.4866],[-74.9859,41.483],[-74.9835,41.4808],[-74.9799,41.4788],[-74.9741,41.4779],[-74.9658,41.4765],[-74.9591,41.477],[-74.9541,41.4783],[-74.9501,41.4799],[-74.9467,41.4822],[-74.942,41.4837],[-74.9383,41.4842],[-74.9351,41.4835],[-74.9346,41.4834],[-74.9311,41.4818],[-74.9277,41.4796],[-74.9235,41.4777],[-74.9204,41.4763],[-74.9178,41.4752],[-74.9149,41.474],[-74.9132,41.4717],[-74.9119,41.469],[-74.9114,41.4664],[-74.9085,41.4628],[-74.9057,41.4606],[-74.9048,41.46],[-74.9013,41.459],[-74.8986,41.458],[-74.8976,41.4574],[-74.8966,41.4567],[-74.8946,41.4552],[-74.8931,41.4532],[-74.8931,41.4508],[-74.8949,41.4481],[-74.8974,41.4463],[-74.8979,41.444],[-74.8976,41.4417],[-74.8958,41.4399],[-74.8932,41.4391],[-74.8866,41.4391],[-74.8805,41.4408],[-74.8748,41.4425],[-74.8705,41.4443],[-74.8668,41.4452],[-74.8659,41.4451],[-74.8631,41.4447],[-74.8577,41.444],[-74.8516,41.4416],[-74.8473,41.4395],[-74.8468,41.4392],[-74.8431,41.437],[-74.8404,41.4352],[-74.8366,41.4341],[-74.8348,41.4336],[-74.8316,41.4338],[-74.8305,41.4342],[-74.8283,41.435],[-74.8258,41.4364],[-74.8229,41.4379],[-74.8211,41.4392],[-74.8178,41.4413],[-74.8141,41.4427],[-74.8104,41.4426],[-74.808,41.4417],[-74.8062,41.4394],[-74.805,41.4367],[-74.8032,41.434],[-74.8016,41.4314],[-74.8001,41.429],[-74.7977,41.4251],[-74.7953,41.4235],[-74.7929,41.4231],[-74.7886,41.423],[-74.7849,41.4244],[-74.7812,41.4257],[-74.7774,41.4264],[-74.7769,41.4265],[-74.7726,41.427],[-74.7677,41.4259],[-74.7671,41.4258],[-74.7628,41.4247],[-74.7579,41.4247],[-74.7561,41.4246],[-74.7536,41.4255],[-74.7506,41.4274]]]},\"properties\":{\"name\":\"Pike\",\"state\":\"PA\"}}]}","contact":"Director, Pennsylvania Water Science Center
U.S. Geological Survey
215 Limekiln Road
New Cumberland, PA 17070-2424
http://pa.water.usgs.gov
Several streams used for recreational activities, such as fishing, swimming, and boating, in Chester County, Pennsylvania, are known to have periodic elevated concentrations of fecal coliform bacteria, a type of bacteria used to indicate the potential presence of fecally related pathogens that may pose health risks to humans exposed through water contact. The availability of near real-time continuous stream discharge, turbidity, and other water-quality data for some streams in the county presents an opportunity to use surrogates to estimate near real-time concentrations of fecal coliform (FC) bacteria and thus provide some information about associated potential health risks during recreational use of streams.
The U.S. Geological Survey (USGS), in cooperation with the Chester County Health Department (CCHD) and the Chester County Water Resources Authority (CCWRA), has collected discrete stream samples for analysis of FC concentrations during March–October annually at or near five gaging stations where near real-time continuous data on stream discharge, turbidity, and water temperature have been collected since 2007 (or since 2012 at 2 of the 5 stations). In 2014, the USGS, in cooperation with the CCWRA and CCHD, began to develop regression equations to estimate FC concentrations using available near real-time continuous data. Regression equations included possible explanatory variables of stream discharge, turbidity, water temperature, and seasonal factors calculated using Julian Day with base-10 logarithmic (log) transformations of selected variables.
The regression equations were developed using the data from 2007 to 2015 (101–106 discrete bacteria samples per site) for three gaging stations on Brandywine Creek (West Branch Brandywine Creek at Modena, East Branch Brandywine Creek below Downingtown, and Brandywine Creek at Chadds Ford) and from 2012 to 2015 (37–38 discrete bacteria samples per site) for one station each on French Creek near Phoenixville and White Clay Creek near Strickersville. Fecal coliform bacteria data collected by USGS in 2016 (about nine samples per site) were used to validate the equations. The best-fit regression equations included log turbidity and seasonality factors computed using Julian Day as explanatory variables to estimate log FC concentrations at all five stream sites. The adjusted coefficient of determination for the equations ranged from 0.61 to 0.76, with the strength of the regression equations likely affected in part by the limited amount and variability of FC bacteria data. During summer months, the estimated and measured FC concentrations commonly were greater than the Pennsylvania Department of Environmental Protection established standards of 200 and 400 colonies per 100 milliliters for water contact from May through September at the 5 stream sites, with concentrations typically higher at 2 sites (White Clay Creek and West Branch Brandywine Creek at Modena) than at the other 3 sites. The estimated concentrations of FC bacteria during the summer months commonly were higher than measured concentrations and therefore could be considered cautious estimates of potential human-health risk. Additional water-quality data are needed to maintain and (or) improve the ability of regression equations to estimate FC concentrations by use of surrogate data.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20175075","collaboration":"Prepared in cooperation with the Chester County Health Department and Chester County Water Resources Authority","usgsCitation":"Senior, L.A., 2017, Estimated fecal coliform bacteria concentrations using near real-time continuous water-quality and streamflow data from five stream sites in Chester County, Pennsylvania, 2007–16: U.S. Geological Survey Scientific Investigations Report 2017–5075, 46 p., https://doi.org/10.3133/sir20175075.","productDescription":"Report: x, 46 p.; Appendix 1-5; Data Release","numberOfPages":"60","onlineOnly":"Y","additionalOnlineFiles":"Y","ipdsId":"IP-084822","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":345650,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2017/5075/coverthb.jpg"},{"id":345651,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2017/5075/sir20175075.pdf","text":"Report","size":"11.2 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2017-5075"},{"id":345652,"rank":3,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2017/5075/sir20175075_appendix1.pdf","text":"Appendix 1","size":"436 KB","linkFileType":{"id":1,"text":"pdf"},"linkHelpText":"- Model Archive Summary for Best-Fit Regression Developed to Estimate Fecal Coliform Concentration at Station 01480617; West Branch Brandywine Creek at Modena, Pennsylvania"},{"id":345653,"rank":4,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2017/5075/sir20175075_appendix2.pdf","text":"Appendix 2","size":"434 KB","linkFileType":{"id":1,"text":"pdf"},"linkHelpText":"- Model Archive Summary for Best-Fit Regression Developed to Estimate Fecal Coliform Concentration at Station 01480870; East Branch Brandywine Creek below Downingtown, Pennsylvania"},{"id":345654,"rank":5,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2017/5075/sir20175075_appendix3.pdf","text":"Appendix 3","size":"429 KB","linkFileType":{"id":1,"text":"pdf"},"linkHelpText":"- Model Archive Summary for Best-Fit Regression Developed to Estimate Fecal Coliform Concentration at Station 01481000; Brandywine Creek at Chadds Ford, Pennsylvania"},{"id":345655,"rank":6,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2017/5075/sir20175075_appendix4.pdf","text":"Appendix 4","size":"348 KB","linkFileType":{"id":1,"text":"pdf"},"linkHelpText":"- Model Archive Summary for Best-Fit Regression Developed to Estimate Fecal Coliform Concentration at Station 01472157; French Creek near Phoenixville, Pennsylvania"},{"id":345656,"rank":7,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2017/5075/sir20175075_appendix5.pdf","text":"Appendix 5","size":"371 KB","linkFileType":{"id":1,"text":"pdf"},"linkHelpText":"- Model Archive Summary for Best-Fit Regression Developed to Estimate Fecal Coliform Concentration at Station 01478245; White Clay Creek near Strickersville, Pennsylvania"},{"id":345657,"rank":8,"type":{"id":30,"text":"Data Release"},"url":"https://doi.org/10.5066/F79W0DC8","text":"USGS data release","description":"USGS data release","linkHelpText":"- Archival data for regression models developed to estimate fecal coliform concentrations at five stream sites, Chester County, Pennsylvania (2017): U.S. Geological Survey"}],"country":"United States","state":"Pennsylvania","county":"Chester County","geographicExtents":"{\"type\":\"FeatureCollection\",\"features\":[{\"type\":\"Feature\",\"geometry\":{\"type\":\"Polygon\",\"coordinates\":[[[-75.6968,40.2417],[-75.6912,40.2388],[-75.6894,40.2378],[-75.6864,40.2387],[-75.6784,40.2436],[-75.6741,40.2458],[-75.6705,40.2466],[-75.6645,40.2461],[-75.6549,40.2428],[-75.6478,40.2404],[-75.6406,40.2371],[-75.6304,40.2347],[-75.6209,40.2305],[-75.6186,40.2277],[-75.6151,40.2245],[-75.6114,40.2244],[-75.6078,40.2258],[-75.6047,40.2275],[-75.6059,40.2294],[-75.6076,40.2326],[-75.6088,40.2348],[-75.6081,40.2366],[-75.605,40.2389],[-75.6014,40.2379],[-75.5997,40.2365],[-75.5973,40.2347],[-75.591,40.2214],[-75.5835,40.21],[-75.5801,40.2045],[-75.5796,40.2004],[-75.5766,40.1981],[-75.5724,40.1967],[-75.5694,40.1966],[-75.5676,40.1975],[-75.5645,40.2006],[-75.5644,40.2029],[-75.5655,40.207],[-75.5661,40.2093],[-75.5636,40.2101],[-75.5606,40.2096],[-75.5589,40.2073],[-75.5554,40.2023],[-75.5503,40.19],[-75.544,40.1794],[-75.5387,40.1739],[-75.527,40.1664],[-75.5275,40.1492],[-75.5239,40.1468],[-75.5184,40.1475],[-75.5127,40.1595],[-75.503,40.1593],[-75.5,40.1563],[-75.5036,40.1506],[-75.5107,40.1422],[-75.5088,40.1347],[-75.4905,40.1253],[-75.4729,40.1287],[-75.4611,40.1241],[-75.4627,40.119],[-75.4691,40.1169],[-75.4719,40.1116],[-75.4693,40.1066],[-75.4618,40.1027],[-75.4633,40.0971],[-75.4563,40.0945],[-75.4558,40.0876],[-75.4401,40.0941],[-75.4369,40.0899],[-75.42,40.0966],[-75.3927,40.0604],[-75.3669,40.0723],[-75.361,40.0668],[-75.3702,40.062],[-75.3732,40.0602],[-75.3811,40.0572],[-75.4012,40.0475],[-75.4025,40.0471],[-75.4086,40.0436],[-75.4128,40.0418],[-75.4106,40.0373],[-75.4076,40.0336],[-75.406,40.0295],[-75.4139,40.0242],[-75.4207,40.0202],[-75.4311,40.0118],[-75.4508,39.9958],[-75.452,39.9949],[-75.4532,39.994],[-75.4521,39.9926],[-75.4455,39.9925],[-75.4437,39.9925],[-75.4412,39.9933],[-75.4401,39.9915],[-75.4372,39.9865],[-75.4385,39.9842],[-75.4398,39.9811],[-75.4399,39.9793],[-75.4423,39.9788],[-75.4446,39.9807],[-75.4726,39.968],[-75.4993,39.9557],[-75.5024,39.9544],[-75.5079,39.9518],[-75.5152,39.9483],[-75.5224,39.9452],[-75.5243,39.9443],[-75.5202,39.9397],[-75.5191,39.9374],[-75.5306,39.9322],[-75.526,39.9239],[-75.5315,39.9218],[-75.5366,39.9305],[-75.5427,39.9274],[-75.5398,39.9242],[-75.5447,39.922],[-75.5424,39.9183],[-75.5502,39.9152],[-75.5468,39.9093],[-75.5553,39.9058],[-75.5576,39.9086],[-75.5601,39.9072],[-75.5583,39.904],[-75.562,39.9023],[-75.5711,39.897],[-75.573,39.8943],[-75.5714,39.8879],[-75.5799,39.8835],[-75.5822,39.8854],[-75.5834,39.8849],[-75.5852,39.8863],[-75.5888,39.8846],[-75.5842,39.8804],[-75.5981,39.8747],[-75.5952,39.8724],[-75.5934,39.8697],[-75.5935,39.8683],[-75.5959,39.8652],[-75.599,39.862],[-75.6003,39.8602],[-75.6015,39.858],[-75.601,39.8562],[-75.5975,39.8539],[-75.5939,39.8515],[-75.5946,39.8488],[-75.5965,39.8457],[-75.5978,39.8416],[-75.5973,39.8379],[-75.6146,39.835],[-75.6308,39.8314],[-75.6464,39.827],[-75.647,39.8268],[-75.6661,39.82],[-75.6775,39.8156],[-75.6928,39.8074],[-75.7056,39.7991],[-75.7177,39.7912],[-75.724,39.7866],[-75.7268,39.7845],[-75.7378,39.775],[-75.7476,39.7653],[-75.7551,39.756],[-75.7611,39.7478],[-75.7662,39.7393],[-75.77,39.731],[-75.7723,39.7231],[-75.7875,39.7231],[-76.0148,39.7228],[-76.1392,39.7223],[-76.1373,39.7262],[-76.1337,39.728],[-76.1307,39.728],[-76.1266,39.7265],[-76.1236,39.7242],[-76.1188,39.726],[-76.1187,39.7301],[-76.1205,39.7333],[-76.1198,39.7364],[-76.1144,39.7368],[-76.1115,39.735],[-76.1121,39.7318],[-76.1134,39.7287],[-76.1104,39.7268],[-76.1051,39.7254],[-76.0996,39.7285],[-76.0965,39.7326],[-76.0959,39.7362],[-76.0988,39.738],[-76.1018,39.7399],[-76.1018,39.7421],[-76.1011,39.7449],[-76.0957,39.7448],[-76.0909,39.7452],[-76.0873,39.7474],[-76.0842,39.7537],[-76.0841,39.7592],[-76.0804,39.7609],[-76.0678,39.7626],[-76.066,39.7644],[-76.0654,39.7671],[-76.0659,39.7708],[-76.0628,39.7734],[-76.0616,39.7752],[-76.0615,39.7789],[-76.0567,39.7802],[-76.0537,39.7819],[-76.0506,39.7846],[-76.0481,39.79],[-76.0444,39.7963],[-76.0377,39.8026],[-76.0352,39.808],[-76.0303,39.813],[-76.0308,39.8175],[-76.032,39.8207],[-76.0265,39.8247],[-76.0253,39.826],[-76.0252,39.8301],[-76.0234,39.831],[-76.0191,39.8319],[-76.0191,39.8337],[-76.0202,39.8378],[-76.023,39.8464],[-76.0217,39.8518],[-76.0211,39.8537],[-76.0181,39.8545],[-76.0163,39.854],[-76.0127,39.8531],[-76.0103,39.8531],[-76.0091,39.8544],[-76.007,39.8666],[-76.0051,39.8712],[-76.0039,39.873],[-76.0015,39.8738],[-75.9991,39.8734],[-75.9974,39.8715],[-75.9956,39.8701],[-75.9932,39.8697],[-75.9926,39.8706],[-75.9908,39.8719],[-75.9877,39.8732],[-75.9871,39.8746],[-75.9877,39.8768],[-75.9912,39.8801],[-75.9905,39.8828],[-75.9899,39.8868],[-75.9879,39.8927],[-75.9885,39.895],[-75.9902,39.8977],[-75.9943,39.901],[-75.9961,39.9028],[-75.9957,39.9236],[-75.9962,39.9259],[-75.998,39.9273],[-75.9968,39.9282],[-75.9938,39.9277],[-75.9926,39.9268],[-75.9914,39.9272],[-75.9902,39.9286],[-75.9859,39.9308],[-75.9841,39.9308],[-75.9823,39.9307],[-75.9811,39.9316],[-75.9805,39.9334],[-75.9822,39.9362],[-75.9875,39.9399],[-75.9915,39.9481],[-75.9921,39.9513],[-75.992,39.9544],[-75.9901,39.958],[-75.9889,39.9607],[-75.987,39.9634],[-75.9869,39.9675],[-75.9722,39.9855],[-75.964,40.0008],[-75.9628,40.0026],[-75.956,40.0125],[-75.9504,40.0197],[-75.935,40.0394],[-75.9354,40.0471],[-75.9361,40.0689],[-75.9365,40.0807],[-75.9403,40.0989],[-75.9413,40.1066],[-75.9412,40.1093],[-75.9315,40.1138],[-75.9139,40.1212],[-75.9018,40.1261],[-75.8757,40.1371],[-75.8604,40.1464],[-75.8494,40.154],[-75.7773,40.1997],[-75.7724,40.2028],[-75.7602,40.2085],[-75.7322,40.2231],[-75.6986,40.2408],[-75.6968,40.2417]]]},\"properties\":{\"name\":\"Chester\",\"state\":\"PA\"}}]}","contact":"Director, Pennsylvania Water Science Center
U.S. Geological Survey
215 Limekiln Road
New Cumberland, PA 17070-2424
Laurel Hill Creek is considered one of the most pristine waterways in southwestern Pennsylvania and has high recreational value as a high-quality cold-water fishery; however, the upper parts of the basin have documented water-quality impairments. Groundwater and surface water are withdrawn for public water supply and the basin has been identified as a Critical Water Planning Area (CWPA) under the State Water Plan. The U.S. Geological Survey, in cooperation with the Somerset County Conservation District, collected data and developed modeling tools to support the assessment of water-quality and water-quantity issues for a basin designated as a CWPA. Streams, springs, and groundwater wells were sampled for water quality in 2007. Streamflows were measured concurrent with water-quality sampling at main-stem sites on Laurel Hill Creek and tributaries in 2007. Stream temperatures were monitored continuously at five main-stem sites from 2007 to 2010. Water usage in the basin was summarized for 2003 and 2009 and a Water-Analysis Screening Tool (WAST) developed for the Pennsylvania State Water Plan was implemented to determine whether the water use in the basin exceeded the “safe yield” or “the amount of water that can be withdrawn from a water resource over a period of time without impairing the long-term utility of a water resource.” A groundwater and surface-water flow (GSFLOW) model was developed for Laurel Hill Creek and calibrated to the measured daily streamflow from 1991 to 2007 for the streamflow-gaging station near the outlet of the basin at Ursina, Pa. The CWPA designation requires an assessment of current and future water use. The calibrated GSFLOW model can be used to assess the hydrologic effects of future changes in water use and land use in the basin.
Analyses of samples collected for surface-water quality during base-flow conditions indicate that the highest nutrient concentrations in the main stem of Laurel Hill Creek were at sites in the northeastern part of the basin where agricultural activity is prominent. All of the total nitrogen (N) and a majority of the total phosphorus (P) concentrations in the main stem exceeded regional nutrient criteria levels of 0.31 and 0.01 milligrams per liter (mg/L), respectively. The highest total N and total P concentrations in the main stem were 1.42 and 0.06 mg/L, respectively. Tributary sites with the highest nutrient concentrations are in subbasins where treated wastewater is discharged, such as Kooser Run and Lost Creek. The highest total N and total P concentrations in subbasins were 3.45 and 0.11 mg/L, respectively. Dissolved chloride and sodium concentrations were highest in the upper part of the basin downstream from Interstate 76 because of road deicing salts. The mean base-flow concentrations of dissolved chloride and sodium were 117 and 77 mg/L, respectively, in samples from the main stem just below Interstate 76, and the mean concentrations in Clear Run were 210 and 118 mg/L, compared to concentrations less than 15 mg/L in tributaries that were not affected by highway runoff. Water quality in forested tributary subbasins underlain by the Allegheny and Pottsville Formations was influenced by acidic precipitation and, to a lesser extent, the underlying geology as indicated by pH values less than 5.0 and corresponding specific conductance ranging from 26 to 288 microsiemens per centimeter at 25 degrees Celsius for some samples; in contrast, pH values for main stem sites ranged from 6.6 to 8.5. Manganese (Mn) was the only dissolved constituent in the surface-water samples that exceeded the secondary maximum contaminant level (SMCL). More than one-half the samples from the main stem had Mn concentrations exceeding the SMCL level of 50 micrograms per liter (μg/L), whereas only 19 percent of samples from tributaries exceeded the SMCL for Mn.
Stream temperatures along the main stem of Laurel Hill Creek became higher moving downstream. During the summer months of June through August, the daily mean temperatures at the five sites exceeded the limit of 18.9 degrees Celsius (°C) for a cold-water fishery. The maximum instantaneous values for each site ranged from 27.2 to 32.8 °C.
Water-quality samples collected at groundwater sites (wells and springs) indicate that wells developed within the Mauch Chunk Formation had the best water quality, whereas wells developed within the Allegheny and Pottsville Formations yielded the poorest water quality. Waters from the Mauch Chunk Formation had the highest median pH (7.6) and alkalinity (80 mg/L calcium carbonate) values. The lowest pH and alkalinity median values were in waters from the Allegheny and Pottsville Formations. Groundwater samples collected from wells in the Allegheny and Pottsville Formations also had the highest concentrations of dissolved iron (Fe) and dissolved Mn. Seventy-eight percent of the groundwater samples collected from the Allegheny Formation exceeded the SMCL of 300 μg/L for Fe and 50 μg/L for Mn. Forty-three and 62 percent of the groundwater samples collected from the Pottsville Formation exceeded the SMCL for iron and Mn, respectively. The highest Fe and Mn concentrations for surface waters were measured for tributaries draining the Pottsville Formation. The highest median Fe concentration for tributaries was in samples from streams draining the Allegheny Formation.
During base-flow conditions, the streamflow per unit area along the main stem of Laurel Hill Creek was lowest in the upper parts of the basin [farthest upstream site 0.07 cubic foot per second per square mile (ft3/s/mi2)] and highest (two sites averaging about 0.20 (ft3/s/mi2) immediately downstream from Laurel Hill Lake in the center of the basin. Tributaries with the highest streamflow per unit area were those subbasins that drain the western ridge of the Laurel Hill Creek Basin. The mean streamflow per unit area for tributaries draining areas that extend into the western ridge and draining eastern or central sections was 0.24 and 0.05 ft3/s/mi2, respectively. In general, as the drainage area increased for tributary basins, the streamflow per unit area increased.
Criteria established by the Pennsylvania Department of Environmental Protection indicate that the safe yield of water withdrawals from the Laurel Hill Creek Basin is 1.43 million gallons per day (Mgal/d). Water-use data for 2009 indicate that net (water withdrawals subtracted by water discharges) water withdrawals from groundwater and surface-water sources in the basin were approximately 1.93 Mgal/d. Water withdrawals were concentrated in the upper part of the basin with approximately 80 percent of the withdrawals occurring in the upper 36 mi2 of the basin. Three subbasins—Allen Creek, Kooser Run, and Shafer Run— in the upper part were affected the most by water withdrawals such that safe yields were exceeded by more than 1,000 percent in the first two and more than 500 percent in the other. In the subbasin of Shafer Run, intermittent streamflow characterizes sections that historically have been perennial.
The GSFLOW model of the Laurel Hill Creek Basin is a simple one-layer representation of the groundwater flow system. The GSFLOW model was primarily calibrated to reduce the error term associated with base-flow periods. The total amount of observed streamflow at the Laurel Hill Creek at Ursina, Pa. streamflow-gaging station and the simulated streamflow were within 0.1 percent over the entire modeled period; however, annual differences between simulated and observed streamflow showed a range of -27 to 24 percent from 1992 to 2007 with nine of the years having less than a 10-percent difference. The primary source of simulated streamflow in the GSFLOW model was the subsurface (interflow; 62 percent), followed by groundwater (25 percent) and surface runoff (13 percent). Most of the simulated subsurface flow that reached the stream was in the form of slow flow as opposed to preferential (fast) interflow.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20165082","collaboration":"Prepared in cooperation with the Somerset County Conservation District","usgsCitation":"Galeone, D.G., Risser, D.W., Eicholtz, L.W., and Hoffman, S.A., 2017, Water quality and quantity and simulated surface-water and groundwater flow in the Laurel Hill Creek Basin, southwestern Pennsylvania, 1991–2007: U.S. Geological Survey Scientific Investigations Report 2016–5082, 85 p., https://doi.org/10.3133/sir20165082.","productDescription":"Report: vii, 85 p.; Appendices 1, 4","startPage":"1","endPage":"85","numberOfPages":"97","onlineOnly":"Y","additionalOnlineFiles":"Y","ipdsId":"IP-006526","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":343500,"rank":3,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2016/5082/sir20165082_appendix1.xlsx","text":"Appendix 1","linkHelpText":"- Concentrations of selected water-quality constituents and values of selected physical characteristics in surface-water samples collected during low-flow conditions in the Laurel Hill Creek Basin, southwestern, Pennsylvania, June and September 2007"},{"id":343501,"rank":4,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/sir/2016/5082/sir20165082_appendix4.xlsx","text":"Appendix 4","linkHelpText":"- Concentrations of selected water-quality constituents and values of selected physical characteristics in groundwater samples collected in the Laurel Hill Creek Basin, southwestern, Pennsylvania, summer and fall 2007"},{"id":343499,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2016/5082/sir20165082.pdf","text":"Report","size":"13.9 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2016-5082"},{"id":343498,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2016/5082/coverthb.jpg"}],"country":"United States","state":"Pennsylvania","otherGeospatial":"Laurel Creek Hill Basin","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -78.88320922851562,\n 40.25228042623786\n ],\n [\n -78.89007568359375,\n 40.26276066437183\n ],\n [\n -78.88458251953125,\n 40.27219149074575\n ],\n [\n -78.91204833984375,\n 40.282668644462895\n ],\n [\n -78.92303466796875,\n 40.28895415740959\n ],\n [\n -79.06585693359375,\n 40.29104919850652\n ],\n [\n -79.112548828125,\n 40.2155868104582\n ],\n [\n -79.12902832031249,\n 40.20614809577503\n ],\n [\n -79.14825439453125,\n 40.18307014852534\n ],\n [\n -79.1510009765625,\n 40.166281254206545\n ],\n [\n -79.17160034179688,\n 40.16942948827397\n ],\n [\n -79.18121337890625,\n 40.12534092477937\n ],\n [\n -79.20730590820312,\n 40.12954106843822\n ],\n [\n -79.22241210937499,\n 40.11273893669507\n ],\n [\n -79.24850463867188,\n 40.10013461308659\n ],\n [\n -79.27734374999999,\n 40.093831575516134\n ],\n [\n -79.44488525390625,\n 39.86547951378614\n ],\n [\n -79.39682006835938,\n 39.83595916247957\n ],\n [\n -79.39132690429688,\n 39.826467782187414\n ],\n [\n -79.34051513671875,\n 39.82752244475985\n ],\n [\n -79.3212890625,\n 39.816975090490004\n ],\n [\n -79.3048095703125,\n 39.80431612840032\n ],\n [\n -79.31167602539062,\n 39.78004660226123\n ],\n [\n -79.30892944335938,\n 39.75154536393759\n ],\n [\n -79.288330078125,\n 39.734650174341866\n ],\n [\n -79.25125122070312,\n 39.729369578088736\n ],\n [\n -79.21554565429688,\n 39.727257226326174\n ],\n [\n -79.16885375976562,\n 39.74415422820842\n ],\n [\n -79.14688110351562,\n 39.75471275080197\n ],\n [\n -79.12628173828125,\n 39.77160302089718\n ],\n [\n -79.1070556640625,\n 39.80431612840032\n ],\n [\n -79.09332275390625,\n 39.82752244475985\n ],\n [\n -79.06585693359375,\n 39.823303697329386\n ],\n [\n -79.05075073242186,\n 39.84439484396462\n ],\n [\n -79.05349731445312,\n 39.86547951378614\n ],\n [\n -79.0631103515625,\n 39.89709437260048\n ],\n [\n -79.08096313476562,\n 39.91289633555756\n ],\n [\n -79.09469604492188,\n 39.926588421909436\n ],\n [\n -79.0850830078125,\n 39.92764154592116\n ],\n [\n -79.04937744140625,\n 39.95501708352986\n ],\n [\n -79.03152465820312,\n 39.98027708862265\n ],\n [\n -79.02603149414062,\n 39.998163944585805\n ],\n [\n -79.01229858398438,\n 40.01604611654875\n ],\n [\n -79.00405883789061,\n 40.01604611654875\n ],\n [\n -78.98483276367188,\n 40.02130468739707\n ],\n [\n -78.96560668945312,\n 40.02235635293741\n ],\n [\n -78.9642333984375,\n 40.04128356064847\n ],\n [\n -78.97109985351562,\n 40.04654018618778\n ],\n [\n -78.95187377929688,\n 40.0833252155441\n ],\n [\n -78.93814086914062,\n 40.111688665595956\n ],\n [\n -78.92715454101562,\n 40.12009038025332\n ],\n [\n -78.85711669921875,\n 40.1452892956766\n ],\n [\n -78.8543701171875,\n 40.1715282298637\n ],\n [\n -78.84201049804688,\n 40.19461010387381\n ],\n [\n -78.84475708007812,\n 40.207196906764054\n ],\n [\n -78.86398315429686,\n 40.214538129296336\n ],\n [\n -78.88320922851562,\n 40.25228042623786\n ]\n ]\n ]\n }\n }\n ]\n}","contact":"Director, Pennsylvania Water Science Center
U.S. Geological Survey
215 Limekiln Road
New Cumberland, PA 17070
A previously developed regional groundwater flow model was used to simulate the effects of changes in pumping rates on groundwater-flow paths and extent of recharge discharging to wells for a contaminated fractured bedrock aquifer in southeastern Pennsylvania. Groundwater in the vicinity of the North Penn Area 7 Superfund site, Montgomery County, Pennsylvania, was found to be contaminated with organic compounds, such as trichloroethylene (TCE), in 1979. At the time contamination was discovered, groundwater from the underlying fractured bedrock (shale) aquifer was the main source of supply for public drinking water and industrial use. As part of technical support to the U.S. Environmental Protection Agency (EPA) during the Remedial Investigation of the North Penn Area 7 Superfund site from 2000 to 2005, the U.S. Geological Survey (USGS) developed a model of regional groundwater flow to describe changes in groundwater flow and contaminant directions as a result of changes in pumping. Subsequently, large decreases in TCE concentrations (as much as 400 micrograms per liter) were measured in groundwater samples collected by the EPA from selected wells in 2010 compared to 2005‒06 concentrations.
To provide insight on the fate of potentially contaminated groundwater during the period of generally decreasing pumping rates from 1990 to 2010, steady-state simulations were run using the previously developed groundwater-flow model for two conditions prior to extensive remediation, 1990 and 2000, two conditions subsequent to some remediation 2005 and 2010, and a No Pumping case, representing pre-development or cessation of pumping conditions. The model was used to (1) quantify the amount of recharge, including potentially contaminated recharge from sources near the land surface, that discharged to wells or streams and (2) delineate the areas contributing recharge that discharged to wells or streams for the five conditions.
In all simulations, groundwater divides differed from surface-water divides, partly because of differences in stream elevations and because of geologic structure and pumping. In the 1990 and 2000 simulations, all recharge in and near the vicinity of North Penn Area 7 discharged to wells, but in the 2005 and 2010 simulations some recharge in this area discharged to streams, indicating possible discharge of contaminated groundwater from North Penn Area 7 sources to streams. As the amount of groundwater withdrawals by wells has declined since 1990, the area contributing recharge to wells in the vicinity of North Penn Area 7 has decreased.
To determine the effect of changes in pumping on flow paths and possible flow-path-related contributions to the observed changes in spatial distribution of contaminants in groundwater from 2005 to 2010, the USGS conducted simulations using the previously developed regional groundwater-flow model using reported pumping and estimated recharge rates for 2005 and 2010. Flow paths from recharge at known contaminant source areas to discharge locations at wells or streams were simulated under steady-state conditions for the two periods. Simulated groundwater-flow paths shifted only slightly from 2005 to 2010 as a result of changes in pumping rates. These slight changes in groundwater-flow paths from known sources of contamination are not coincident with the spatial distribution of observed changes in TCE concentrations from 2005 to 2010, indicating that the decreases of TCE concentrations may be a result of other processes, such as source removal or degradation. Results of the simulations and the absence of increases in TCE-degradation-product concentrations indicate that the decreases of TCE concentrations observed in 2010 may be at least partly related to contaminant-source removal by soil excavation completed in 2005, although additional data would be needed to confirm this preliminary explanation.
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20175014","collaboration":"Prepared in cooperation with the U.S. Environmental Protection Agency","usgsCitation":"Senior, L.A., and Goode, D.J., 2017, Effects of changes in pumping on regional groundwater-flow paths, 2005 and 2010, and areas contributing recharge to discharging wells, 1990–2010, in the vicinity of North Penn Area 7 Superfund site, Montgomery County, Pennsylvania: U.S. Geological Survey Scientific Investigations Report 2017–5014, 36 p., https://doi.org/10.3133/sir20175014.","productDescription":"Report: vi, 36 p.; Data Release","onlineOnly":"Y","additionalOnlineFiles":"N","ipdsId":"IP-077142","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":341375,"rank":3,"type":{"id":30,"text":"Data Release"},"url":"https://dx.doi.org/10.5066/F7FN14BQ","text":"USGS data release","description":"USGS data release"},{"id":341337,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2017/5014/sir20175014.pdf","text":"Report","size":"4.61 MB","linkFileType":{"id":1,"text":"pdf"}},{"id":341336,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2017/5014/coverthb.jpg"}],"country":"United States","state":"Pennsylvania","county":"Montgomery County","otherGeospatial":"North Penn Area 7 Superfund Site","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -75.304167,\n 40.244444\n ],\n [\n -75.263333,\n 40.244444\n ],\n [\n -75.263333,\n 40.205556\n ],\n [\n -75.304167,\n 40.205556\n ],\n [\n -75.304167,\n 40.244444\n ]\n ]\n ]\n }\n }\n ]\n}","contact":"Director, Pennsylvania Water Science Center
U.S. Geological Survey
215 Limekiln Road
New Cumberland, PA 17070
An evaluation of trends in hydrologic and water quality conditions and estimation of water budgets through 2013 was done by the U.S. Geological Survey in cooperation with the Chester County Water Resources Authority. Long-term hydrologic, meteorologic, and biologic data collected in Chester County, Pennsylvania, which included streamflow, groundwater levels, surface-water quality, biotic integrity, precipitation, and air temperature were analyzed to determine possible trends or changes in hydrologic conditions. Statistically significant trends were determined by applying the Kendall rank correlation test; the magnitudes of the trends were determined using the Sen slope estimator. Water budgets for eight selected watersheds were updated and a new water budget was developed for the Marsh Creek watershed. An average water budget for Chester County was developed using the eight selected watersheds and the new Marsh Creek water budget.
Annual and monthly mean streamflow, base flow, and runoff were analyzed for trends at 10 streamgages. The periods of record at the 10 streamgages ranged from 1961‒2013 to 1988‒2013. The only statistically significant trend for annual mean streamflow was for West Branch Brandywine Creek near Honey Brook, Pa. (01480300) where annual mean streamflow increased 1.6 cubic feet per second (ft3/s) per decade. The greatest increase in monthly mean streamflow was for Brandywine Creek at Chadds Ford, Pa. (01481000) for December; the increase was 47 ft3/s per decade. No statistically significant trends in annual mean base flow or runoff were determined for the 10 streamgages. The greatest increase in monthly mean base flow was for Brandywine Creek at Chadds Ford, Pa. (01481000) for December; the increase was 26 ft3/s per decade.
The magnitude of peaks greater than a base streamflow was analyzed for trends for 12 streamgages. The period of record at the 12 stream gages ranged from 1912‒2012 to 2004–11. Fifty percent of the streamgages showed a small statistically significant increase in peaks greater than the base streamflow. The greatest increase was for Brandywine Creek at Chadds Ford, Pa. (01481000) during 1962‒2012; the increase was 1.8 ft3/s per decade. There were no statistically significant trends in the number of floods equal to or greater than the 2-year recurrence interval flood flow.
Twenty‒one monitoring wells were evaluated for statistically significant trends in annual mean water level, minimum annual water level, maximum annual water level, and annual range in water-level fluctuations. For four wells, a small statistically significant increase in annual mean water level was determined that ranged from 0.16 to 0.7 feet per decade. There was poor or no correlation between annual mean groundwater levels and annual mean streamflow and base flow. No correlation was determined between annual mean groundwater level and annual precipitation. Despite rapid population growth and land-use change since 1950, there appears to have been little or no detrimental effects on groundwater levels in 21 monitoring wells.
Long-term precipitation and temperature data were available from the West Chester (1893‒2013) and Phoenixville, Pa. (1915‒2013) National Oceanic and Atmospheric Administration (NOAA) weather stations. No statistically significant trends in annual mean precipitation or annual mean temperature were determined for either station. Both weather stations had a significant decrease in the number of days per year with precipitation greater than or equal to 0.1 inch. Annual mean minimum and maximum temperatures from the NOAA Southeastern Piedmont Climate Division increased 0.2 degrees Fahrenheit (F) per decade between 1896 and 2014. The number of days with a maximum temperature equal to or greater than 90 degrees F increased at West Chester and decreased at Phoenixville. No statistically significant trend was determined for annual snowfall amounts.
Data from 1974 to 2013 for three stream water-quality monitors in the Brandywine Creek watershed were evaluated. The monitors are on the West Branch Brandywine Creek at Modena, Pa. (01480617), East Branch Brandywine Creek below Downingtown, Pa. (01480870), and Brandywine Creek at Chadds Ford, Pa. (01481000). Statistically significant upward trends were determined for annual mean specific conductance at all three stations, indicating the total dissolved solids load has been increasing. If the current trend continues, the annual mean specific conductance could almost double from 1974 to 2050. The increase in specific conductance likely is due to increases in chloride concentrations, which have been increasing steadily over time at all three stations. No correlation was found between monthly mean specific conductance and monthly mean streamflow or base flow. Statistically significant upward trends in pH were determined for all three stations. Statistically significant upward trends in stream temperature were determined for East Branch Brandywine Creek below Downingtown, Pa. (01480870) and Brandywine Creek at Chadds Ford, Pa. (01481000). The stream water-quality data indicate substantial increases in the minimum daily dissolved oxygen concentrations in the Brandywine Creek over time.
The Chester County Index of Biotic Integrity (CC-IBI) determined for 1998‒2013 was evaluated for the five biological sampling sites collocated with streamgages. CC-IBI scores are based on a 0‒100 scale with higher scores indicating better stream quality. Statistically significant upward trends in the CC-IBI were determined for West Branch Brandywine Creek at Modena, Pa. (01480617) and East Branch Brandywine Creek below Downingtown, Pa. (01480870). No correlation was found between the CC-IBI and streamflow, precipitation, or stream specific conductance, pH, temperature, or dissolved oxygen concentration.
A Chester County average water budget was developed using the nine estimated watershed water budgets. Average precipitation was 48.4 inches, and average streamflow was 21.4 inches. Average runoff and base flow were 8.3 and 13.1 inches, respectively, and average evapotranspiration and estimation of errors was 27.2 inches.\"
","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/sir20175025","collaboration":"Prepared in cooperation with the Chester County Water Resources Authority","usgsCitation":"Sloto, R.A., and Reif, A.G., 2017, Evaluation of long-term trends in hydrologic and water-quality conditions, and estimation of water budgets through 2013, Chester County, Pennsylvania (ver.1.1, July 2017): U.S. Geological Survey Scientific Investigations Report 2017–5025, 59 p., https://doi.org/10.3133/sir20175025.","productDescription":"vii, 59 p.","numberOfPages":"71","onlineOnly":"Y","additionalOnlineFiles":"Y","ipdsId":"IP-064731","costCenters":[{"id":532,"text":"Pennsylvania Water Science Center","active":true,"usgs":true}],"links":[{"id":341981,"rank":2,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/sir/2017/5025/sir20175025.pdf","text":"Report","size":"8.49 MB","linkFileType":{"id":1,"text":"pdf"},"description":"SIR 2017-5025"},{"id":343456,"rank":3,"type":{"id":25,"text":"Version History"},"url":"https://pubs.usgs.gov/sir/2017/5025/versionHist.txt"},{"id":341980,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/sir/2017/5025/coverthb2.jpg"}],"country":"United States","state":"Pennsylvania","county":"Chester County","geographicExtents":"{\"type\":\"FeatureCollection\",\"features\":[{\"type\":\"Feature\",\"geometry\":{\"type\":\"Polygon\",\"coordinates\":[[[-75.6968,40.2417],[-75.6912,40.2388],[-75.6894,40.2378],[-75.6864,40.2387],[-75.6784,40.2436],[-75.6741,40.2458],[-75.6705,40.2466],[-75.6645,40.2461],[-75.6549,40.2428],[-75.6478,40.2404],[-75.6406,40.2371],[-75.6304,40.2347],[-75.6209,40.2305],[-75.6186,40.2277],[-75.6151,40.2245],[-75.6114,40.2244],[-75.6078,40.2258],[-75.6047,40.2275],[-75.6059,40.2294],[-75.6076,40.2326],[-75.6088,40.2348],[-75.6081,40.2366],[-75.605,40.2389],[-75.6014,40.2379],[-75.5997,40.2365],[-75.5973,40.2347],[-75.591,40.2214],[-75.5835,40.21],[-75.5801,40.2045],[-75.5796,40.2004],[-75.5766,40.1981],[-75.5724,40.1967],[-75.5694,40.1966],[-75.5676,40.1975],[-75.5645,40.2006],[-75.5644,40.2029],[-75.5655,40.207],[-75.5661,40.2093],[-75.5636,40.2101],[-75.5606,40.2096],[-75.5589,40.2073],[-75.5554,40.2023],[-75.5503,40.19],[-75.544,40.1794],[-75.5387,40.1739],[-75.527,40.1664],[-75.5275,40.1492],[-75.5239,40.1468],[-75.5184,40.1475],[-75.5127,40.1595],[-75.503,40.1593],[-75.5,40.1563],[-75.5036,40.1506],[-75.5107,40.1422],[-75.5088,40.1347],[-75.4905,40.1253],[-75.4729,40.1287],[-75.4611,40.1241],[-75.4627,40.119],[-75.4691,40.1169],[-75.4719,40.1116],[-75.4693,40.1066],[-75.4618,40.1027],[-75.4633,40.0971],[-75.4563,40.0945],[-75.4558,40.0876],[-75.4401,40.0941],[-75.4369,40.0899],[-75.42,40.0966],[-75.3927,40.0604],[-75.3669,40.0723],[-75.361,40.0668],[-75.3702,40.062],[-75.3732,40.0602],[-75.3811,40.0572],[-75.4012,40.0475],[-75.4025,40.0471],[-75.4086,40.0436],[-75.4128,40.0418],[-75.4106,40.0373],[-75.4076,40.0336],[-75.406,40.0295],[-75.4139,40.0242],[-75.4207,40.0202],[-75.4311,40.0118],[-75.4508,39.9958],[-75.452,39.9949],[-75.4532,39.994],[-75.4521,39.9926],[-75.4455,39.9925],[-75.4437,39.9925],[-75.4412,39.9933],[-75.4401,39.9915],[-75.4372,39.9865],[-75.4385,39.9842],[-75.4398,39.9811],[-75.4399,39.9793],[-75.4423,39.9788],[-75.4446,39.9807],[-75.4726,39.968],[-75.4993,39.9557],[-75.5024,39.9544],[-75.5079,39.9518],[-75.5152,39.9483],[-75.5224,39.9452],[-75.5243,39.9443],[-75.5202,39.9397],[-75.5191,39.9374],[-75.5306,39.9322],[-75.526,39.9239],[-75.5315,39.9218],[-75.5366,39.9305],[-75.5427,39.9274],[-75.5398,39.9242],[-75.5447,39.922],[-75.5424,39.9183],[-75.5502,39.9152],[-75.5468,39.9093],[-75.5553,39.9058],[-75.5576,39.9086],[-75.5601,39.9072],[-75.5583,39.904],[-75.562,39.9023],[-75.5711,39.897],[-75.573,39.8943],[-75.5714,39.8879],[-75.5799,39.8835],[-75.5822,39.8854],[-75.5834,39.8849],[-75.5852,39.8863],[-75.5888,39.8846],[-75.5842,39.8804],[-75.5981,39.8747],[-75.5952,39.8724],[-75.5934,39.8697],[-75.5935,39.8683],[-75.5959,39.8652],[-75.599,39.862],[-75.6003,39.8602],[-75.6015,39.858],[-75.601,39.8562],[-75.5975,39.8539],[-75.5939,39.8515],[-75.5946,39.8488],[-75.5965,39.8457],[-75.5978,39.8416],[-75.5973,39.8379],[-75.6146,39.835],[-75.6308,39.8314],[-75.6464,39.827],[-75.647,39.8268],[-75.6661,39.82],[-75.6775,39.8156],[-75.6928,39.8074],[-75.7056,39.7991],[-75.7177,39.7912],[-75.724,39.7866],[-75.7268,39.7845],[-75.7378,39.775],[-75.7476,39.7653],[-75.7551,39.756],[-75.7611,39.7478],[-75.7662,39.7393],[-75.77,39.731],[-75.7723,39.7231],[-75.7875,39.7231],[-76.0148,39.7228],[-76.1392,39.7223],[-76.1373,39.7262],[-76.1337,39.728],[-76.1307,39.728],[-76.1266,39.7265],[-76.1236,39.7242],[-76.1188,39.726],[-76.1187,39.7301],[-76.1205,39.7333],[-76.1198,39.7364],[-76.1144,39.7368],[-76.1115,39.735],[-76.1121,39.7318],[-76.1134,39.7287],[-76.1104,39.7268],[-76.1051,39.7254],[-76.0996,39.7285],[-76.0965,39.7326],[-76.0959,39.7362],[-76.0988,39.738],[-76.1018,39.7399],[-76.1018,39.7421],[-76.1011,39.7449],[-76.0957,39.7448],[-76.0909,39.7452],[-76.0873,39.7474],[-76.0842,39.7537],[-76.0841,39.7592],[-76.0804,39.7609],[-76.0678,39.7626],[-76.066,39.7644],[-76.0654,39.7671],[-76.0659,39.7708],[-76.0628,39.7734],[-76.0616,39.7752],[-76.0615,39.7789],[-76.0567,39.7802],[-76.0537,39.7819],[-76.0506,39.7846],[-76.0481,39.79],[-76.0444,39.7963],[-76.0377,39.8026],[-76.0352,39.808],[-76.0303,39.813],[-76.0308,39.8175],[-76.032,39.8207],[-76.0265,39.8247],[-76.0253,39.826],[-76.0252,39.8301],[-76.0234,39.831],[-76.0191,39.8319],[-76.0191,39.8337],[-76.0202,39.8378],[-76.023,39.8464],[-76.0217,39.8518],[-76.0211,39.8537],[-76.0181,39.8545],[-76.0163,39.854],[-76.0127,39.8531],[-76.0103,39.8531],[-76.0091,39.8544],[-76.007,39.8666],[-76.0051,39.8712],[-76.0039,39.873],[-76.0015,39.8738],[-75.9991,39.8734],[-75.9974,39.8715],[-75.9956,39.8701],[-75.9932,39.8697],[-75.9926,39.8706],[-75.9908,39.8719],[-75.9877,39.8732],[-75.9871,39.8746],[-75.9877,39.8768],[-75.9912,39.8801],[-75.9905,39.8828],[-75.9899,39.8868],[-75.9879,39.8927],[-75.9885,39.895],[-75.9902,39.8977],[-75.9943,39.901],[-75.9961,39.9028],[-75.9957,39.9236],[-75.9962,39.9259],[-75.998,39.9273],[-75.9968,39.9282],[-75.9938,39.9277],[-75.9926,39.9268],[-75.9914,39.9272],[-75.9902,39.9286],[-75.9859,39.9308],[-75.9841,39.9308],[-75.9823,39.9307],[-75.9811,39.9316],[-75.9805,39.9334],[-75.9822,39.9362],[-75.9875,39.9399],[-75.9915,39.9481],[-75.9921,39.9513],[-75.992,39.9544],[-75.9901,39.958],[-75.9889,39.9607],[-75.987,39.9634],[-75.9869,39.9675],[-75.9722,39.9855],[-75.964,40.0008],[-75.9628,40.0026],[-75.956,40.0125],[-75.9504,40.0197],[-75.935,40.0394],[-75.9354,40.0471],[-75.9361,40.0689],[-75.9365,40.0807],[-75.9403,40.0989],[-75.9413,40.1066],[-75.9412,40.1093],[-75.9315,40.1138],[-75.9139,40.1212],[-75.9018,40.1261],[-75.8757,40.1371],[-75.8604,40.1464],[-75.8494,40.154],[-75.7773,40.1997],[-75.7724,40.2028],[-75.7602,40.2085],[-75.7322,40.2231],[-75.6986,40.2408],[-75.6968,40.2417]]]},\"properties\":{\"name\":\"Chester\",\"state\":\"PA\"}}]}","edition":"Version 1.0: Originally posted June 2,2017; Version 1.1: July 10, 2017","contact":"Director, Pennsylvania Water Science Center
U.S. Geological Survey
215 Limekiln Road
New Cumberland, PA 17070