WHY REGULATING STOMWATER IS IMPORTANT
Stormwater runoff is one of the most significant sources of pollution in the nation. In Rhode Island, stormwater is the single greatest cause of water quality problems for the rivers assessed [but note that only 38% of the river miles are assessed, so the condition of 62% is not known]. At some locations the impact of stormwater is greater than pollution discharged by industrial and sewage sources. When rain falls on impervious surfaces such as roads, parking lots and rooftops, or on construction sites, it can pick up and transport into surface waters numerous pollutants such as algae-promoting nutrients, pathogens, heavy metals, sediments and toxic substances. In addition to polluting streams, rivers, lakes, estuaries and coastal waters with these contaminants, stormwater runoff has other serious ecological impacts, including habitat degradation, stream bank erosion, flooding and channelization. As the EPA has acknowledged: “Storm water runoff from lands modified by human activity can harm surface water resources and, in turn, cause or contribute to an exceedance of water quality standards by changing natural hydrologic patterns, accelerating stream flows, destroying aquatic habitat, and elevating pollutant concentrations and loading.” Stormwater discharges from storm water sewers have been found to be “a major source of water quality impairment nationwide.”
Stormwater runoff also has significant public health consequences, including contamination of surface drinking water sources, and bacterial pollution leading to shellfish and beach closures. Finally, the improper management of stormwater runoff can interrupt natural hydrologic cycles in a way that prevents recharge of groundwater resources.
Control of stormwater runoff can significantly improve water quality and can also address the many other negative impacts of stormwater, listed above. Requiring facilities to develop detailed stormwater management plans, especially plans that take into consideration the specific circumstances of particular facility types, is a big step forward in controlling this source of pollution.
Blackstone River Coalition
Watershed-wide Volunteer Water Quality Monitoring Program
Procedure for Developing 2006 Monitoring Season Report Card
1. Samples are collected and tested on the second Saturday of the month from April to November. Sites must be sampled at least 6 times out of 8 possible monitoring events. Monthly raw data is color coded by parameter according to guidance provided by MA DEP. See chart below.
Category/Indicator Units Excellentgreen Goodyellow Fairorange Poorred
AESTHETICS
Turbidity NTU 0-1 greater than 1, less than 5 5 - 50 >50
CHEMICAL
Dissolved Oxygen Cold water >8 mg/l >6 – 7 mg/l 5 – 6 mg/l <5 mg/l
Warm water >6 mg/l 5 – < 6 mg/l 4 – <5 mg/l <4 mg/l
% Saturation 91 – 110 % 71 – 90 % 50 – 70 % < 50%
Temperature Cold water < 15ºC(<59ºF) 15ºC - <20ºC(59ºF - <68ºF) 20ºC – 24ºC(68ºF – 75.5ºF) >24ºC (>75.2ºF)
Warm water < 24ºC(<75.2ºF) 24ºC - <27ºC(75.2º - <80.6ºF) 27ºC – 28ºC(80.6ºF – 83ºF) >28ºC (>83ºF)
NUTRIENTS
Orthophosphate as P mg/l <.025 .025 - <.05 .05 - .1 >.1
Nitrate as N mg/l <0.3 0.3 - <.6 0.6 – 0.9 >0.9
Adapted from: MA DEP’s SMART Monitoring Watershed Report Card Criteria, Kimball,Warren.2005.unpublished. DEP, Worcester.
2. Parameters are grouped into the following categories: aesthetics, water temperature, dissolved oxygen (DO), DO % saturation, and nutrients
· aesthetics includes the following measurements: turbidity, water appearance, water odor, nuisance aquatic vegetation, erosion, presence of trash a visual assessment of turbidity and knowledge of the site
· water temperature
· dissolved oxygen
· water temperature
· nutrients includes the following parameters: nitrate and orthophosphate
3. The report card includes an overall grade for each category (for each site monitored)
· aesthetics
o using best professional judgment all measurements are assessed to determine an overall grade. This is the most subjective category.
· water temperature
o for sites designated as a cold water fishery the grade is determined by the lowest grade received even if it is a one time occurrence. For other sites if there is one outlier (low grade) the results are evaluated as a whole and best professional judgment is used to determine grade
· dissolved oxygen
o if one or more monitoring event includes a DO grade in the red (poor), the site receives a red (poor) overall grade
o if one or more monitoring event includes a DO grade in the orange (fair), the site receives an orange (fair) overall grade
o if one or more monitoring event includes a DO grade in the yellow (good), the site receives a yellow (good) overall grade
o if every monitoring event results in a DO grade in the green (excellent), the site receives a green (excellent) overall grade
o if the site experiences one or more no flow events it receives a red (poor) overall grade
· DO % saturation
o for sites designated as a cold water fishery the grade is determined by the lowest grade received even if it is a one time occurrence. For other sites if there is one outlier (low grade) the results are evaluated as a whole and best professional judgment is used to determine grade
· nutrients
o averages are calculated for both nitrate (as nitrogen) and orthophosphate (as phosphorous)
o overall site grades are assigned primarily based on the phosphorous average, due to phosphorous being the limiting nutrient in fresh water.
o if the average phosphorous grade falls into the orange (fair) or yellow (good) category, but more than one monitoring event has a phosphorous red (poor) rating (excluding wet weather events*), the site is given an overall grade of red (poor)
* April, May and June were considered wet weather events
4. Report card includes the following notations
· *cwf indicates designated cold water fishery, which means cold water standards for DO and water temperature were used
· **in the site location column indicates the site experienced no flow conditions during one or more sampling events during the season
For more information please contact Tammy Gilpatrick, Program Coordinator, Brcoaltion@yahoo.com or visit our website zaptheblackstone.org
Email us
cdovidio@clf.org
DEM has issued the draft stormwater permit for industrial facili
Blackstone Corridor Keepers and Water Monitoring
Phosporous Treatment Reduction