NOAA-AOML Report on Water Quality in Brevard
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Quote from the NOAA-AOML report - "The exact effect of the Southeast Shoal on discharges is not known; however, the shoal will certainly affect water circulation in the near shore. Given the proximity of the Southeast Shoal off of Cape Canaveral, large vessels need to head SE upon leaving or entering the port. At 4 nautical miles from shore along this course, discharges will occur in waters less than 15 m deep and currents flowing north will intersect the Southeast Shoal. Even at 12 nautical miles from shore along this course the water depth is only 20 m. Not until the 30 m depth contour is reached can the possibility of significant interaction with the Shoal be truly discounted and depending on course this can be well beyond the 12 nm limit."

An indirect threat to human health could occur if “elevated” nutrients in coastal waters were derived from sewage, because the sewage could contain infectious organisms. Epidemiological studies suggest that swimming in waters contaminated with fecal bacteria does pose a health risk (Cabelli, 1979; Dufour, 1984; Cheung, 1990).

Animal sewage (e.g., dairy, pig, dog, bird) is unsanitary; however, human sewage poses the greatest risk to human health because it has the greatest potential to carry human pathogens. Coastal waters can become contaminated with nutrients and fecal bacteria from sewage outfalls, leaking septic tanks, run-off, boat discharges, animal deposits, and from contaminated groundwater (Howington et al., 1992; Paul, 1995; Scarlatos, 2001; Payton, 2004; Boehm et al., 2004).

Testing the Waters, 2006
A guide to Water Quality on Vacation Beaches in Florida.
NRDC
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Beaches were under swimming advisories for 3,428 days in 2005; there were also 13 extended advisories lasting 7 to 13 consecutive weeks and 20 permanent advisories lasting more than 13 consecutive weeks.

Florida red tides were a particular problem in 2005. There were more fish kills and other events, such as abnormal fish appearance and discolored waters, attributed to red tides in the first three months of 2005 than during the same time period in four of the previous five years.

In March 2005, the well-publicized die-off of several dozen manatees in southwest Florida waters was potentially linked to red tides. Preliminary research from scientists working in southwest Florida’s Lee County on both red tides and red-drift algae (nontoxic micro-algae whose blooms are also triggered by the presence of nutrients in water) suggests that occurrences of such blooms are worsening, are linked to wastewater discharges and other nutrient sources, and are initiated near shore, closer to sources of human-made pollution, rather than offshore, as previously thought.

Cruise Control
A Report on How Cruise Ships Affect the Marine Environment
May 2002 - The Ocean Conservancy
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Human sewage can carry enteric bacteria, pathogens, diseases, viruses, the eggs of intestinal parasites, and harmful nutrients.

Within U.S.. waters, oil and hazardous substances are regulated under the Clean
Water Act and the Oil Pollution Act, which require that oily wastes discharged within 12 nautical miles of shore have an oil content fewer than 15 ppm. Oily bilge water discharged from 12 to 200 miles (the boundary of the u.s. Exclusive Economic Zone) offshore must have an oil content less than 100 ppm. Cruise ships can generate 1,300 to 37,000 gallons of oily bilge water per day, depending on the size and age of the ship.4,5 Royal Caribbean Cruises Ltd. reports that approximately half of the total is treated and discharged at sea; the remainder is retained in on-board tanks and treated on shore when the ship reaches port. However, reporting is not required, and reports were not available from other companies.

In 1994, U.S. Coast Guard investigators discovered that Royal Caribbean Cruises Ltd. engineers constructed illegal plumbing lines to bypass oil pollution treatment equipment, which were removed during Coast Guard inspections and reinstalled after the ship passed inspection. In 1998, RCCL pled guilty to seven felony counts for conspiracy to discharge hazardous wastes and obstruct justice and was fined $8 million. The following year, RCCL was fined another $18 million after pleading guilty to a 21-count indictment for the fleetwide practice of discharging oil-contaminated bilge water and contaminated gray water and for making false statements.6 On April 19, 2002, the U.S. Attorney for the Southern District of Florida reported that Carnival Cruises was ordered to pay $18 million in fines and community service for illegally discharging oily waste into the ocean and for falsifying records between 1996 and 2001.

Unlike the discharge of land-based sewage and other pollutants, the Clean Water Act does not regulate sewage discharged by ships under the National Pollution Discharge Elimination System (npdes) Permit Program. Instead, the cwa requires vessels to install and use Coast Guard-approved marine sanitation devices (msds) capable of treating or holding raw sewage. Federal regulations prohibit the discharge within three nautical miles of shore of untreated or inadequately treated sewage with a coliform bacterial count greater than 200 colonies per 100 milliliters, or total suspended solids exceeding 150 mg/100 ml. Beyond the three-mile limit, however, ships can discharge raw sewage whenever they wish, which can wash back to shore.

Estimates of cruise ship sewage production range from five to 10 gallons per person per day, or 15,000 to 30,000 gallons per day for a typical cruise ship carrying 3,000 passengers and crew.10,11 The cruise line industry reports that its policy is to discharge treated black water or gray water only when underway and not while in ports. But it is difficult to confirm whether practice follows policy. To its credit, however, the industry has offered to work with regulators to identify especially sensitive areas where wastewater should not be discharged, and the industry has agreed not to dump within 10 miles of certain Alaskan ports.12 Unlike the discharge of land-based sewage and other pollutants, the Clean Water Act does not regulate sewage discharged by ships under the National Pollution Discharge Elimination System (npdes) Permit Program. Instead, the cwa requires vessels to install and use Coast Guard-approved marine sanitation devices (msds) capable of treating or holding raw sewage. Federal regulations prohibit the discharge within three nautical miles of shore of untreated or inadequately treated sewage with a coliform bacterial count greater than 200 colonies per 100 milliliters, or total suspended solids exceeding 150 mg/100 ml. Beyond the three-mile limit, however, ships can discharge raw sewage whenever they wish, which can wash back to shore. 13 A Report by The Ocean Conservancy Until now, very little research existed documenting the actual performance of msds on cruise ships. Recently, however, the state of Alaska conducted a study under the oversight of the u.s. Coast Guard and the Alaska Department of Environmental Conservation.13 Samples of treated black water and gray water registered fecal coliform levels as high as 9 to 24 million colonies per 100 milliliter sample, exceeding federal limits by 10,000 to 100,000 times. None of the 22 cruise ships tested was in full compliance with all black water standards, and 75 percent of the “treated” sewage samples exceeded federal standards for fecal coliform.

During the summer of 2001, nearly half of the bacterial and suspended solids samples collected from five ships exceeded the amount allowed by state water quality standards. Cruise ships currently operating in Alaska and elsewhere generally collect and treat sewage in one of two varieties of msds: a biological system employing aeration and clarification to biologically digest the sewage, or a chemical treatment system that masticates the waste and adds up to eight times the volume of salt water and chlorine. Following treatment, the waste is pumped into holding tanks, where it is usually combined with the ship’s gray water. Some of these tanks can hold as much as 396,000 gallons, or one to three days’ production of gray water and treated black water. These wastes are held until discharged overboard.

Since chlorine is itself a highly toxic substance, especially to the eggs and larvae of many marine organisms, the chlorine that enters the receiving water upon discharge of the waste can have significant environmental impacts.

Although Coast Guard inspectors certify waste treatment equipment during their quarterly inspections, they are not required to test discharges to determine whether or not they comply with mandated water quality standards.