Stonnwater and Sediment 



coliform is not sanitary waste, but is attributable to dogs and wildlife. Using measured 

 fecal loadings from dog waste, the authors predict that the volume of dog waste necessary 

 to account for the overall geometric mean value of fecal coliform in discharged runoff could 

 be supplied by a two to three day accumulation (Heufelder, 1988). 



The impact of animal populations on an adjacent waterbody is governed by a number of 

 factors relating to the probability of the waste being entrained in stormwater and the 

 survival characteristics of the waste. Entrainment is affected by the percent of impervious 

 area in the drainage basin, and by the drainage characteristics of the remaining lawns, 

 landscaped sites, and other land uses. In urbanizing areas, drainage is primarily designed 

 to deliver runoff to storm drains, shortening delivery time to receiving waters. Regarding 

 survival of the wastes, sunlight and cold weather inhibit coliform survival, while wann 

 weather enhances survival and rep^roduction. In that regard, turbidity increases survival by 

 inhibiting light penetration in receiving waters (Heufelder, 1988). 



Other conclusions of the same study regarding release of pathogens from protected 

 "reservoirs" may be of additional relevance in Narragansett Bay. Heufelder (1988) found 

 that within Buttermilk Bay both the sediment and decaying eel grass and wrack remaining 

 after ebb of tide served to act as reservoirs and accumulators of fecal coliform. When 

 dislodged or eluded by tidal action or storm events, coliform held in these sources returned 

 to the water column, "possibly resulting in severe degradation of water quality in addition 

 to that imparted by the existing storm drains." 



Groundwater entering Buttermilk Bay was also found to contain entrained fecal 

 indicator organisms. Factors governing entrainment of bacteria and viruses are complex 

 (see related chapter on ISDS), but saturated conditions arc known to promote bacterial 

 entrainment to groundwater. Storm or recharge events increase the velocity of lateral 

 groundwater flow, resulting in the movement of entrained pathogens to the "breakout 

 point" to the Bay itself. Mechanisms of transport of organisms across the "breakout 

 barrier" interface between saturated soil and estuarine waters are poorly understood, but the 

 author suggests that groundwater inputs may account for some observed loadings 

 (Heufelder, 1988). 



GENERAL FINDINGS 



Although some important tools are already in place, stormwater 

 management and sediment/erosion control authorities need to be further 

 developed, refined, and updated. The lack of state stormwater management 

 legislation is a major impediment to effective action, and needs to be 

 rectified. Similarly, the existing sediment and erosion control statute 

 requires strengthening. Statutory language in both cases should include statements of 

 findings, implementation steps, priorities, responsibilities, and adequate funding 

 authorizations, and should specifically reference related state and federal requirements. 



As in other non-point source issue areas, institutional arrangements 

 which are in place to address stormwater management and sediment/erosion 

 control are unable to anticipate cumulative effects of development on water 

 quality. OEM's antidegradation policy is not presenUy being implemented in a manner 

 which allows effective evaluation of incremental impacts. Similarly, CRMC has been 

 unable to use its coastal ecosystem protection mandate to adequately evaluate and mitigate 

 potential cumulative effects. 



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