Predictability of swimming prohibitions by observational parameters: a proactive public health policy, Stamford, Connecticut, 1989-2004.Introduction
The method used by the city of Stamford laboratory to determine what conditions warrant a preemptive pre·emp·tive or pre-emp·tive
1. Of, relating to, or characteristic of preemption.
2. Having or granted by the right of preemption.
a. closure may be applicable to any recreational water body. Knowing that bacterial elevations can be due to the flushing of urban areas through rivers, streams, and storm drains storm drain
1. A storm sewer.
2. A catch basin. , as opposed to a point source (U.S. Environmental Protection Agency Environmental Protection Agency (EPA), independent agency of the U.S. government, with headquarters in Washington, D.C. It was established in 1970 to reduce and control air and water pollution, noise pollution, and radiation and to ensure the safe handling and [U.S. EPA EPA eicosapentaenoic acid.
n.pr See acid, eicosapentaenoic.
n. ], 1995) helps direct resources. In 2000, U.S. EPA listed Stamford and two states as having established models for preemptive closure of bathing waters. The hope is that this will assist and prompt others to establish their own methods and parameters for recreational water closures (U.S. EPA, 1999).
Prior to 1990, beach closures were based on bacteria tests taken from designated points along the beach. If one or more samples from a beach were found to contain more than the recommended level of bacteria, the beach was closed and more samples were taken. Sampling continued until acceptable levels were obtained and then the beach was reopened. Samples were usually taken on Monday, so if test results were elevated, retesting could occur prior to the weekend. Samples were rarely collected if it was raining and rainfall amounts were generally not recorded. Before 1988, a few individual samples had been found with high bacteria counts but no cause was determined.
Several factors occurred to necessitate ne·ces·si·tate
tr.v. ne·ces·si·tat·ed, ne·ces·si·tat·ing, ne·ces·si·tates
1. To make necessary or unavoidable.
2. To require or compel. the previous procedures to be revised. First, certain areas apart from the bathing areas became "conditionally open" for recreational shellfish shellfish, popular name for certain edible mollusks (see Mollusca), e.g., oysters, clams, and scallops, and for certain edible crustaceans, e.g., crabs, lobsters, and shrimps. All are aquatic invertebrates with shells; they are not fish. harvesting (State of Connecticut Marine Aquaculture aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasing share of world fisheries production. Division, 1988). "Conditionally open" is a protocol based on rain monitoring. Second, elevated sample results in 1988 prompted a comprehensive sanitary survey that raised more questions than it answered. Finally, the primary indicator organism was changed to the enterococcus enterococcus /en·tero·coc·cus/ (en?ter-o-kok´us) pl. enterococ´ci an organism belonging to the genus Enterococcus.
Enterococcus /En·tero·coc·cus/ ( group (this was a 48-hour test in 1989), and during that indicator organism's evaluation in 1989 the summer season was extremely wet. Rainfall was collected and measured by a rain gauge operated at the Stamford Health Department and confirmed by the NOAA NOAA
National Oceanic and Atmospheric Administration
Noun 1. NOAA - an agency in the Department of Commerce that maps the oceans and conserves their living resources; predicts changes to the earth's environment; Station #5N-06-7970-3 at the Stamford Museum and Nature Center.
Standard methods for all sampling, transport, and holding methods were followed as referenced in the current edition of Standard Methods for the Examination of Water and Wastewater (Greenberg, Clesceri, & Eaton, 1992). All testing was performed within an hour of receipt in the lab. All bacteria testing used the membrane filtration technique using portions of a 100 mL sample. Typical aliquots would be 10 mL for total and fecal fecal /fe·cal/ (fe´k'l) pertaining to or of the nature of feces.
Relating to or composed of feces.
pertaining to or of the nature of feces. coliform coliform /col·i·form/ (kol´i-form) pertaining to fermentative gram-negative enteric bacilli, sometimes restricted to those fermenting lactose, e.g., Escherichia, Klebsiella, or Enterobacter. testing and 20 mL for enterococcus testing. M-Endo broth broth
liquid media for culturing microorganisms.
cooked meat broth
a medium useful for culturing anaerobic bacteria.
one modified to permit growth by selected bacteria. was used for total coliform testing, m-FC broth with rosolic acid was used for fecal coliform testing, and mE agar was initially used for the enterococcus testing until the m-EI, U.S. EPA 1600 testing became available in 1998.
Until 1988, recreational waters at 11 points on four beaches were sampled weekly for approximately 15 weeks each summer.
Counts above 1,000 total coliform for 100 mL or 400 fecal coliform per 100 mL were considered elevated.
After a particularly rainy period at the end of July in 1988, several sets of samples failed, indicating a new problem. A broad survey was undertaken, with over 500 samples taken during the season to determine where the source of the problem might be. Samples were collected daily from the beaches, at marinas, points offshore from the beaches, known shoreline septic septic /sep·tic/ (sep´tik) pertaining to sepsis.
1. Of, relating to, having the nature of, or affected by sepsis.
2. systems, storm drains, pump stations, and river outflows. Any unusual objects washing into the swimming area were noted, identified, and analyzed. Testing for fecal streptococcus streptococcus (strĕp'təkŏk`əs), any of a group of gram-positive bacteria, genus Streptococcus, some of which cause disease. was also added to total and fecal coliform testing.
Only enterococcus and fecal coliform were evaluated after 1989. An elevated value for enterococcus was greater than 61 colonies per 100 mL for a single sample and 33 for a geometric mean (mathematics) geometric mean - The Nth root of the product of N numbers.
If each number in a list of numbers was replaced with their geometric mean, then multiplying them all together would still give the same result. of five or more samples. Fecal coliform levels were used for continuity to past results. From 1989 to 1995, samples were collected when problems were thought to exist or under conditions that needed to be evaluated more extensively, which included high "moon" tides, storms, wind, and high temperatures. In 1995, additional samples were taken and evaluated after rain events less than one inch after a period of dry weather conditions.
The characteristics of each beach were evaluated in 1996 with special emphasis on flows from rivers and storm waters, tidal flows, and man-made and natural barriers.
In 1998, the bacterial analysis of the storm waters and rivers flowing near the beaches were checked. Also in 1998, the affects of discolored dis·col·or
v. dis·col·ored, dis·col·or·ing, dis·col·ors
To alter or spoil the color of; stain.
To become altered or spoiled in color. white Styrofoam-like objects washing ashore days after rain events greater than two inches were assessed.
In 2000, enterococcus limits were adjusted to 104 CFUs/100 mL for a single sample or a geometric mean limit at 35 to reflect the state of Connecticut and U.S. EPA recommendations (State of Connecticut Department of Health Services Department of Health Services may refer to:
Prior to 1988 (i.e., 1967 to 1986), an average of 14 samples out of 170 samples per season were elevated, but in 1988, more than 20 elevated samples occurred in a single two-week period. An additional 400 samples were taken and 48 of those showed high bacterial levels. Results clearly indicated that a simple point source of the elevated bacteria counts did not exist.
In 1989, evaluating enterococcus bacteria as the primary indicator organism showed a correlation between elevated enterococcus levels and rainfall. This correlation was not the same with total and fecal coliforms Fecal coliforms (sometimes faecal coliforms) are facultatively-anaerobic, rod-shaped, gram-negative, non-sporulating bacteria. They are capable of growth in the presence of bile salts or similar surface agents, oxidase negative, and produce acid and gas from lactose within . Using enterococcus values with multiple regression Multiple regression
The estimated relationship between a dependent variable and more than one explanatory variable. and Chi-squared analysis determined that tide, wind, and water temperature were nonsignificant non·sig·nif·i·cant
1. Not significant.
2. Having, producing, or being a value obtained from a statistical test that lies within the limits for being of random occurrence. (p > .05). The data was stratified stratified /strat·i·fied/ (strat´i-fid) formed or arranged in layers.
Arranged in the form of layers or strata. by rain (less than one inch and one inch or more), bacterial level (less than 60 colonies/ 100 mL and greater than or equal to 61 colonies/100 mL), and days after the rain event (less than two and greater than or equal to two), which revealed a significant relationship (p < .01). A higher level of enterococcus bacteria in the bathing water occurred with more rain (Glassman & O'Brien, 1990).
[FIGURE 1 OMITTED]
The evaluations taken from 1988 to 1995 showed significant rainfall events (defined as events greater than one inch or more) were the primary condition that elevated the geometric mean above 33/100 mL for enterococcus bacteria (Glassman & O'Brien, 1990) (Table 1).
Elevated temperature and high tides show an elevated geometric mean until rainfall is factored out, then they show geometric means below 33/100 mL.
In 1993 and 1995, the total amount of rain during the beach season was very light and rain greater than one inch did not occur in the months of June, July, or August. Bacterial counts bacterial count Public health The concentration of coliform bacteria in water, a quantity that loosely correlates with the level of contamination of drinking and recreational waters. See Public water. were greatly influenced by storm water runoff Runoff
The procedure of printing the end-of-day prices for every stock on an exchange onto ticker tape.
If the "tape is late" then it can take a long time to print off all the closing prices. with a rain of 0.7", and some areas were affected with as little as a half inch of rain. The effect caused by less rain was not as widespread and predictable as for that observed after a rainfall greater than an inch, but it can prove to be significant in times of decreased rain during the summer months (Table 2).
In 1996, the physical characteristic of each beach was examined and cumulated data was reviewed (Figure 1).
Cove Island beach is bordered on the east by the outflow of a sizable salt marsh Salt marsh
A maritime habitat characterized by grasses, sedges, and other plants that have adapted to continual, periodic flooding. Salt marshes are found primarily throughout the temperate and subarctic regions. that is fed by a small river draining the eastern portion of Stamford (light industrial, urban, and residential) and the western portion of a strictly residential town.
Horseshoe horseshoe, narrow plate, commonly of iron or steel, shaped to fit a horse's hoof and attached to the hoof by nailing it to the inner edge of the horny wall of the hoof. beach is located in a small cove and is sheltered from direct runoff but has the outlet of a small marina to the west.
Cummings beach has an outlet from a man-made drainage basin drainage basin: see catchment area. and a marina to the west separated by a rock jetty jetty: see coast protection. .
West beach is located to the west of the same drainage basin and marina as Cummings beach but has no barriers to the flow of the outlet.
The east and midsample points at Cummings beach and the Horseshoe beach at Cove Island did not show the same increase in bacteria after significant rain.
Of all the beaches, West beach showed the greatest influence after significant rainfall with the Cove beach Cove Beach, Ontario can mean the following places:
The discolored white Styrofoam-like objects washing ashore days after rain events greater than two inches were analyzed several times. In 1989, total and fecal coliform bacteria coliform bacteria
Rod-shaped bacteria usually found in the intestinal tracts of animals, including humans. Coliform bacteria do not require but can use oxygen, and they do not form spores. They produce acid and gas from the fermentation of lactose sugar. were found in quantities from 1.2 to 5 million colonies per gram. Analysis in other years were consistent with bacteria counts greater than one million CFUs per gram for both fecal coliform and enterococcus bacteria.
The primary chemical constituent is a moderately high hydrocarbon not of petroleum origin determined by high pressure liquid chromatograph chromatograph /chro·mato·graph/ (kro-mat´o-graf)
1. the apparatus used in chromatography.
2. to analyze by chromatography.
1. to analyze by chromatography.
2. and referenced to oleic acid oleic acid /ole·ic ac·id/ (o-le´ik) a monounsaturated 18-carbon fatty acid found in most animal fats and vegetable oils; used in pharmacy as an emulsifier and to assist absorption of some drugs by the skin. by infrared spectrometry spectrometry /spec·trom·e·try/ (spek-trom´e-tre) determination of the wavelengths or frequencies of the lines in a spectrum.
n. (see photo on page 20).
In Stamford, storm water is not combined with the sanitary sewers A sanitary sewer (also called, especially in the UK, a foul sewer) is a type of underground carriage system for transporting sewage from houses or industry to treatment or disposal. and therefore is not treated, but does not discharge directly to the recreational swimming areas (Bell & Romick, 2003). Storm drains were considered a point source in the early eighties because large populations of raccoons were living within the system. Raccoon raccoon, nocturnal New World mammal of the genus Procyon. The common raccoon of North America, Procyon lotor, also called coon, is found from S Canada to South America, except in parts of the Rocky Mts. and in deserts. habitation HABITATION, civil law. It was the right of a person to live in the house of another without prejudice to the property.
2. It differed from a usufruct in this, that the usufructuary might have applied the house to any purpose, as, a store or manufactory; whereas in the storm drains was well documented during "Operation Shellfish," a program that checked all homes and businesses in the area for improper sanitary sewer connections. Raccoon habitation was also considered a primary cause of the high bacterial levels in Stamford's storm drains. This changed in 1991 when a rabies rabies (rā`bēz, ră`–) or hydrophobia (hī'drəfō`bēə), acute viral infection of the central nervous system in dogs, foxes, raccoons, skunks, bats, and other animals, and in epidemic came to the northeast United States United States, officially United States of America, republic (2005 est. pop. 295,734,000), 3,539,227 sq mi (9,166,598 sq km), North America. The United States is the world's third largest country in population and the fourth largest country in area. and the raccoon population was reduced by up to 95% (State of Connecticut Department of Health Services, 1991).
Bacterial levels continued to be elevated after rainfall of one inch or greater even after the collapse of the raccoon population, showing again that the source was human, not animal.
Normal tidal fluctuations do not appear to affect the water quality at the beaches. Unusually high tides, particularly the perigee perigee (pĕr`ĭjē), point nearest the earth in the orbit of a body about the earth. See apsis.
See apogee. tide occurring in summer, might have an influence by washing out storm drains in the same way as rain. The geometric mean of samples taken after the perigee tide was not above 35.
Using enterococcus bacteria only, it was clear that rainfall was the primary influence. The use of total coliform and fecal coliform bacteria did not make the contribution of storm water apparent because some coliform organisms are saprophytes and can bloom in higher water temperatures without being linked to a pollution source (Greenberg, Clesceri, & Eaton, 1992).
Throughout this study, any rain of one inch or greater would cause a number of samples to be elevated, but when conditions had been dry for a period of time, less rain was needed to affect water quality. Figure 2 represents a map of Stamford beaches and Table 3 illustrates the effect of a 0.7-inch rainfall in samples taken several hours after the rain ended. The results of tests taken two days after the initial profile showed no significant bacteria counts at any area. With this issue identified, dry weather conditions were defined as less than two inches of rain in 30 days and less than one inch of rain in 10 days; a half inch of rain is the amount needed to trigger a preemptive closure.
[FIGURE 2 OMITTED]
Sewage grease was an issue in 1988 when it was observed washing into bathing areas, and was initially believed to be the main cause of beach closures during that summer.
More information concerning floatables (Greenberg, Clesceri, & Eaton, 1992) was obtained in 1998, when several of them were observed before they washed onto a beach. Lifeguards reported the appearance of reddish water several days after a problem occurred at a neighboring neigh·bor
1. One who lives near or next to another.
2. A person, place, or thing adjacent to or located near another.
3. A fellow human.
4. Used as a form of familiar address.
v. sewage treatment Sewage treatment
Unit processes used to separate, modify, remove, and destroy objectionable, hazardous, and pathogenic substances carried by wastewater in solution or suspension in order to render the water fit and safe for intended uses. plant due to almost four inches of rain over a two-day period. The town where the problem originated closed their beaches for several weeks. Beaches from a neighboring town located between where the problem originated and Stamford had one beach closed for one week with enterococcus colonies per 100 mL averaging 151 and fecal coliform colonies per 100 mL averaging 868. Stamford's beaches were analyzed and found to contain a significant number of rotifers and jellyfish jellyfish, common name for the free-swimming stage (see polyp and medusa), of certain invertebrate animals of the phylum Cnidaria (the coelenterates). The body of a jellyfish is shaped like a bell or umbrella, with a clear, jellylike material filling most of the but a low level of enterococcus and fecal coliform bacteria. Identification and quantification of these rotifers and comparing this to the saprobic sap·robe
An organism that derives its nourishment from nonliving or decaying organic matter.
[sapro- + Greek bios, life; see gwei- in Indo-European roots. index indicated the water to be moderately to heavily polluted pol·lute
tr.v. pol·lut·ed, pol·lut·ing, pol·lutes
1. To make unfit for or harmful to living things, especially by the addition of waste matter. See Synonyms at contaminate.
2. at the time (Foissner, 1992; Sladecek, 1983) (Table 4). When the sewage grease did wash ashore, the enterococcus levels became elevated until the floatables were no longer present.
If floatables are found in open water, no significant elevation occurs in bacterial counts of the water where they are found. This unexplained characteristic caused some confusion in identifying the floatables as being a component of sewage, but as they washed up on shore and were subject to wave action they broke apart, releasing bacterial contamination.
Lifeguards and marine police were trained to recognize sewage grease and other suspicious events in the waters and to report them to the health department. Beach closures can occur when these items are observed and remain in effect until they stop washing ashore. Usually the marine police observe a slick approaching and are able to give one days' notice before these floatables wash ashore. Lifeguards also report and send samples of any unusual substance found in the water to the health department.
The presence of sewage grease was found to be significant only at the beach where it was found and not at neighboring beaches. The geometric mean of samples taken from beaches where the sewage grease was present was greater than 35/100 mL. The appearance of floatables usually occurred between one and 10 days after a sewage discharge from treatment plants with combined storm water and sewer connections. Some of these discharges were reported and some were assumed, since the plants' capacities were exceeded by rains greater than two inches (Massachusetts Water Resources Authority The Massachusetts Water Resources Authority (MWRA) is a public authority in the Commonwealth of Massachusetts that provides wholesale drinking water and sewage services to certain municipalities and industrial users in the state, primarily in the Boston area. , 1996; U.S. EPA, 1997). The floatable components of these discharges are "grease balls" and a thin, highly visible film or slick that is wind driven.
Perhaps the most difficult issue in using predictive closures is dealing with the public. Their perception is that the water is getting "dirtier" when bathing areas are closed, but in reality it means that the issues and problems of water quality are becoming more apparent. If the water were rarely tested, swimming would almost never be prohibited. The media can be extremely helpful by assisting in explaining the situation ("The Good and the Bad," 1998; Waldman, 1999).
A policy was established to prohibit bathing at beaches using immediately observable ob·serv·a·ble
1. Possible to observe: observable phenomena; an observable change in demeanor. See Synonyms at noticeable.
2. and measurable parameters. Monitoring the beach areas continues on a weekly basis, with special emphasis on sampling immediately after a rain, at low tide or during any other adverse condition that might affect the water quality.
In summary, runoff after a significant rain event affects the quality of water at the recreational beaches in Stamford. What constitutes significant rain may vary according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. the drainage and topography topography (təpŏg`rəfē), description or representation of the features and configuration of land surfaces. Topographic maps use symbols and coloring, with particular attention given to the shape and elevations of terrain. of each beach and according to the rainfall pattern for the season. If more sources of drainage around a beach or the occurrence of drought or near-drought conditions occurs, then less rain is needed to influence water quality. Under conditions of normal or above normal rainfall, one inch of rain is needed to elevate el·e·vate
tr.v. ele·vat·ed, ele·vat·ing, ele·vates
1. To move (something) to a higher place or position from a lower one; lift.
2. To increase the amplitude, intensity, or volume of.
3. bacterial levels in bathing areas with a single source of storm water influx. Under dry weather conditions, a half inch of rain is all that is necessary to affect the bacterial level in the recreational water area. If multiple sources of storm runoff exist, a mere quarter inch of rain can have a significant impact on water quality (State of Connecticut Department of Environmental Protection, 1998).
Establishing a predictive model for beach closures is resource intensive and requires many samples taken under a variety of different conditions. Unusual occurrences of elevated bacterial levels should not be discounted until all possible explanations have been exhausted. Once a predictive model is established, then health of bathers is promoted by prohibiting swimming and potentially preventing disease when studies have shown the risk is highest. This also gives those who go to the recreational bathing areas maximum opportunity to enjoy these areas, since they are not needlessly closed while awaiting a bacterial retest re·test
tr.v. re·test·ed, re·test·ing, re·tests
To test again.
A second or repeated test. .
Acknowledgements: Iliana Ayala, M.S., Research Assistant for Save the Sound, Inc., provided information and direct assistance on rotifer rotifer
Any of about 2,000 species of microscopic, multicellular, water-dwelling invertebrates constituting the class Rotifera, or Rotaria (phylum Aschelminthes; see worm). identification. Thomas J. Murray, Assistant Director of Waste Water Treatment for Westchester County, New York '' Westchester County is a primarily suburban county located in the U.S. state of New York with about 950,000 residents. It is part of the New York Metropolitan Area. It was named after Chester, in England, and the county seat is White Plains. , from 1967 to 1988, provided insight into the problems treatment plants have handling large rain events. Connecticut Agricultural Station provided HPLC HPLC high-performance liquid chromatography.
high performance liquid chromatography.
HPLC High-performance liquid chromatography Lab instrumentation A highly sensitive analytic method in which analytes are placed analysis on floatable material submitted July, 1994.
Corresponding Author: Joseph E. Kuntz, Lab Technician, City of Stamford, Health Department Laboratory, 888 Washington Blvd., Stamford, CT 06901. E-mail: JKuntz@ ci.stamford.ct.us.
Bell, D., & Romick, L. (2003). 2000 & 2003 Triennial tri·en·ni·al
1. Occurring every third year.
2. Lasting three years.
1. A third anniversary.
2. A ceremony or celebration occurring every three years. Evaluation. Hartford, CT: State of Connecticut Department of Agriculture, Bureau of Aquaculture, and Laboratory.
Foissner, W. (1992). Evaluating water quality using protozoa and saprobity indexes. Protocols in Protozoology protozoology /pro·to·zo·ol·o·gy/ (-zo-ol´ah-je) the study of protozoa.
The biological study of protozoa.
the scientific study of protozoa. , B(11), 1?20.
The good and bad about beach closing. (1998, July 20). The Stamford Advocate, p A14.
Glassman, M.J., & O'Brien, G. (1990). Rainfall as a predictor of unacceptable bathing water bacteria level. Paper presented at the Stamford Health Department.
Greenberg, A.E., Clesceri, L.S., & Eaton, A.D. (Eds.) (1992). Standard methods for the examination of water and wastewater (18th ed.). Washington, DC: American Public Health Association The American Public Health Association (APHA) is Washington, D.C.-based professional organization for public health professionals in the United States. Founded in 1872 by Dr. Stephen Smith, APHA has more than 30,000 members worldwide. .
Massachusetts Water Resources Authority. (1996). Combined sewer A combined sewer is a type of sewer system which provides partially separated channels for sanitary sewage and stormwater runoff. This allows the sanitary sewer system to provide backup capacity for the runoff sewer when runoff volumes are unusually high, but it is an antiquated overflows. Boston, MA: Author.
Sladecek, V. (1983). Rotifers as indicators of water quality. Hydrobiologia, 100, 169-201.
State of Connecticut Department of Environmental Protection (1998). Connecticut water bodies not meeting water quality standards, state of Connecticut department of environmental protection report to the United States Environmental Protection Agency "EPA" redirects here. For other uses see EPA (disambiguation) and Environmental Protection Agency.
The Environmental Protection Agency (EPA or sometimes USEPA [section 303(d) list]. Hartford, CT: Author.
State of Connecticut Department of Health Services (1989). Guidelines for monitoring bathing waters and closure protocol. Hartford, CT: Author.
State of Connecticut Department of Health Services. (1991). Connecticut epidemiologist, epidemiology section, 11(3). Hartford, CT: Author.
State of Connecticut Marine Aquaculture Division. (1988). Memorandum of understanding A Memorandum of Understanding (MoU) is a legal document describing a bilateral or multilateral agreement between parties. It expresses a convergence of will between the parties, indicating an intended common line of action and may not imply a legal commitment. between the state of Connecticut Marine Aquaculture Division and the city of Stamford. Hartford, CT: Author. U.S. Environmental Protection Agency Office of Enforcement and Compliance. (1995). Pro-Act fact sheet on storm water pollution prevention, report TI#6727. Washington, DC: Author.
U.S. Environmental Protection Agency Long Island Sound Office, Long Island Sound Study. (1997). Floatable debris. Stamford, CT: Author.
U.S. Environmental Protection Agency Beach Watch Program. (1999). Review of potential modeling tools and approaches to support the beach program. Washington, DC: Author.
Waldman, L. (1999, June 9). Testing the sound's water, Stamford health department monitors shoreline for bacteria. The Stamford Advocate, p. A3.
Joseph Kuntz, R.S.
Robert Murray Robert Murray is the name of:
TABLE 1 Evaluation Using the Geometric Mean under Various Conditions Condition Bacteria No. Geometric Tested Samples Mean All samples Total coliform 291 27.5 Fecal coliform 328 11.9 Enterococcus 569 6.5 Rain < 1.00" Total coliform 71 186 Fecal coliform 71 50 Enterococcus 71 43 Low tide Total coliform 51 13.8 Fecal coliform 58 4.8 Enterococcus 58 3.3 Flood tide Total coliform 127 26.8 Fecal coliform 146 11 Enterococcus 146 6.1 High tide Total coliform 84 47.9 Fecal coliform 88 24.1 Enterococcus 88 13.7 Ebb tide Total coliform 28 19.3 Fecal coliform 35 11.7 Enterococcus 35 5.1 Water temp. < 51[degrees]F Total coliform 11 3.7 Fecal coliform 11 1.9 Enterococcus 14 2.0 Water temp. 51[degrees]F-61[degrees]F Total coliform 84 39.4 Fecal coliform 84 11.8 Enterococcus 84 7.6 Water temp. > 61[degrees]F Total coliform 186 31.1 Fecal coliform 220 14.3 Enterococcus 377 6.2 Condition No. Tested Bacteria Arithmatic Elevated Mean Samples All samples Total coliform 583 24 Fecal coliform 160 21 Enterococcus 96.9 48 Rain < 1.00" Total coliform 1,134 11 Fecal coliform 242 10 Enterococcus 146 32 Low tide Total coliform 373 2 Fecal coliform 112 2 Enterococcus 30 5 Flood tide Total coliform 480 14 Fecal coliform 147 11 Enterococcus 123 15 High tide Total coliform 778 6 Fecal coliform 143 5 Enterococcus 97 20 Ebb tide Total coliform 543 2 Fecal coliform 334 3 Enterococcus 63 7 Water temp. < 51[degrees]F Total coliform 101 0 Fecal coliform 75 0 Enterococcus 51 1 Water temp. 51[degrees]F-61[degrees]F Total coliform 815 13 Fecal coliform 296 10 Enterococcus 212 13 Water temp. > 61[degrees]F Total coliform 512 11 Fecal coliform 124 11 Enterococcus 62 34 TABLE 2 Evaluation of Drought Conditions and the Amount of Rain Causing Closure Conditions Enterococcus/ Summer Samples 100 mL Beach Rain after 0.5" Geometric Amounts to 0.99" Mean Cove Island Normal 21 8.4 Drought 8 29.1 Cummings Normal 14 11.5 Drought 6 54.3 West Normal 8 26.6 Drought 4 399.8 Note. The effects of abnormal events have been removed from this table. TABLE 3 Single Example of Significant Rain in Dry Weather Conditions, 0.73" of Rain Samples Cove Island Horseshoe E M W Low tide samples, 110 90 <5 <5 5 hours after rain ended Low tide samples, <5 <5 No sample <5 2 days later Samples Cummings Beach West Beach E M W N S Low tide samples, 15 <5 605 410 300 5 hours after rain ended Low tide samples, <5 <5 <5 <5 <5 2 days later Note. All values are reported as enterococcus CFUs/100 mL. TABLE 4 Rotifer Determinations Before an Incident of Sewage Grease Washing onto the Shore Date Event(s) 6/17 A two-day rain event of 3.940" occurs and neighboring sewage treatment plants with combined storm and sewer systems are overwhelmed. 6/24 1. Routine sampling occurs in morning. 2. Lifeguards call to report "red water" and samples are taken in the afternoon. 3. Microscopic examination of the water showed large quantities of rotifers and a person familiar with this examination was contacted for assistance. 4. Water determinations before the red color was reported: Enterococcus, 2; Fecal coliforms, 10. 5. Water determinations after red color: Enterococcus Fecal coliforms E. coli 35 180 170 Saprobic Index (Si) Brachionus Encentrum Asplancha Rubens Lupus Brightwelli 85 170 204 Saprobic Index (Si) 3.2 2.4 2.3 6/25 Bacteria determinations: Water Fecal Enterococcus coliforms E. coli 77.5 335 270 Bacteria determination: Sewage grease results in CFUs/g Enterococcus 1,000,000 6/29 Bacteria determinations: Water Fecal Enterococcus coliforms 5 <10 Note. Rotifer determined microscopically by Save the Sound's Research Assistant Iliana Ayala and is reported as number of organisms per 10 fields. Bacterial testing on water was performed by Stamford's Health Department Laboratory and is reported in CFUs/100 mL. Bacterial testing on the solid material was performed by Stamford's Health Department Laboratory and is reported in CFUs/g.