Water-Quality Monitoring for Environmental Management and Source-Water Protection

U.S. Geological SurveyNew England Water Science Center

in cooperation with

Rhode Island Department of Environmental Management

US Department of InteriorUS Geological SurveyU.S. Department of the InteriorU.S. Geological Survey

Monitoring goals:

• Characterize water-quality conditions in 4 major RI streams

• Provide data in a format that is used in reporting water quality conditions (305B reports) and assisting in management decisions

• Collect data that may be used to:Identify long-term trendEstimate constituent loads

Slater Mill, Pawtucket, RI

Station Name Identifier Streamflow data Water-quality data

Blackstone River at Millville, MA 01111230 2008 1971, 1973, 1978-2002, 2007-present

Blackstone River at Manville 01112900 1970, 1979-present 1970, 1978-2002, 2007-present

Blackstone River at Roosevelt St, at Pawtucket

01113895 2003-present 2007-present

Branch River at Forestdale 01111500 1940-present1953, 1954, 1956-57, 1958, 1965-67, 1968, 1969, 1971-72, 1975-2002, 2007-present

Pawtuxet River at Pawtuxet 01116617Nearby gage (01116500)

1939-present 1978-2002, 2007-present

Pawcatuck River at Westerly 01118500 1940-present1952, 1953, 1963, 1967, 1971-73, 1975-2002, 2007-present

Rhode Island water-quality monitoring network:

DRAFT

Analyte

USGS NWQL

Parameter code

Minimum reporting

level

Monthly sampling

Quarterly sampling

Nutrients        

Organic-N + ammonia-N, whole water

625 0.07 mg/L ü ü

Organic-N + ammonia-N, filtered 623 0.07 mg/L ü ü

Ammonia nitrogen 608 0.010 mg/L ü ü

Nitrate + nitrite nitrogen 631 0.04 mg/L ü ü

Nitrite nitrogen 613 0.0010 mg/L ü ü

Total phosphorus, whole water 665 0.004 mg/L ü ü

Total phosphorus, filtered 666 0.0030 mg/L ü ü

Orthophosphate phosphorus 671 0.004 mg/L ü ü

Trace metals        

Cadmium, filtered 1025 0.016 ug/L   ü Chromium, filtered 1030 0.07 ug/L   ü Copper, filtered 1040 0.80 ug/L   ü Lead, filtered 1049 0.025 ug/L   ü Nickel, filtered 1065 0.09 ug/L   ü Zinc, filtered 1090 1.4 ug/L   ü

2014-15 Sampling Plan:

Analyte

USGS NWQL

Parameter code

Minimum reporting

level

Monthly sampling

Quarterly sampling

Major ions        

Calcium, filtered 915 0.022 mg/L ü ü

Magnesium, filtered 925 0.011 mg/L ü ü

Sodium, filtered 930 0.06 mg/L ü ü

Chloride, filtered 940 0.06 mg/L ü ü

Suspended sediment        

SSC 80154 1 mg/L ü ü

Field parameters        

Water temperature 10 0.01 oC ü ü

Specific conductance 95 1.0 uS/cm ü ü

Dissolved oxygen 300 0.1 mg/L ü ü

pH 400   ü ü

2014-15 Sampling Plan:

• Monthly sampling strategy covers the full range of flow conditions at all stations.

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.010

100

1000

10000FLOW ON WATER-QUALITYSAMPLING DATE--Colors showmonth in which sample was taken

11 Nov

2 Feb 3 Mar 4 Apr 5 May 6 Jun 7 Jul 8 Aug 9 Sep 10 Oct

12 Dec

1 Jan

BLACKSTONE R. AT PAWTUCKET (01113895)March 2007-June 2013

ST

RE

AM

FLO

W, i

n cu

bic

feet

per

sec

ond

PERCENT OF TIME EXCEEDING

DRAFT

• Data show seasonal variations in water-quality conditions.

DRAFT

• Flow-weighted trend analysis shows long-term changes in some constituents.

DRAFT

Summary:

• Monthly sampling adequately characterizes full range of flow conditions at all stations

• Sampling locations shown to be well mixed through equal-width-increment isokinetic sampling

• Monthly sampling is suitable to identify long-term trends

• Provide routine, long-term water quality results, formatted for RIDEM’s database, that can be used for a variety of water resource management activities through the USGS cooperative program.

Rhode Island water-quality monitoring network

DRAFT