City of Mandan

The City of Mandan has prepared this report in compliance with Environmental Protection Agency (EPA) regulations. These guidelines require every community water system across the United States (including Mandan's municipally owned and operated system) to create an annual report informing customers about their water quality. This marks the twentieth annual report for Mandan's system, summarizing water quality data for the monitoring period ending December 31, 2017, along with relevant information about potential health effects from detected contaminants.

Mandan sources its water from the Missouri River. At the Mandan Water Treatment Plant, river water undergoes a comprehensive purification process. Initially, water is pumped into pretreatment basins where unpleasant tastes, odors, and suspended sediments are removed. Following pretreatment, water flows through either the original 1958 treatment train or the 1985 plant addition. Both treatment paths include softening, clarification, stabilization, disinfection, and filtration. The plant typically produces approximately 3.05 million gallons per day (MGD) with a capacity of roughly 12 MGD.

Water sources (both tap and bottled) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over land or underground, it dissolves naturally-occurring minerals and, in some cases, radioactive materials, and may pick up substances from animal presence or human activity. Potential contaminants in source water include:

• Microbial Contaminants from sewage treatment plants, septic systems, agricultural operations, and wildlife
• Inorganic Contaminants such as salts and metals, which can be naturally-occurring or result from urban runoff, wastewater discharges, oil/gas production, mining, or farming
• Pesticides and Herbicides from various sources including agriculture, urban stormwater runoff, and residential uses
• Organic Chemical Contaminants, including synthetic and volatile organic chemicals from industrial processes, petroleum production, gas stations, stormwater runoff, and septic systems
• Radioactive Contaminants that may occur naturally or result from oil/gas production and mining activities

All drinking water, including bottled water, may reasonably contain at least small amounts of some contaminants. Their presence doesn't necessarily indicate a health risk. The EPA prescribes regulations limiting contaminant levels in public water systems, while FDA regulations establish similar limits for bottled water, both ensuring public safety.

Some individuals may be particularly vulnerable to water contaminants, including those undergoing chemotherapy, organ transplant recipients, people with HIV/AIDS or immune system disorders, some elderly persons, and infants. These individuals should seek medical advice about their drinking water consumption.

1. Why is beach water sampled?
   State and federal beach legislation (both enacted in 2000) mandate monitoring of public and semi-public beaches for bacterial contamination during bathing seasons. Massachusetts implemented regulatory updates addressing these requirements in 2001. Private beaches aren't subject to these regulations.
2. What defines a public beach?
   A public bathing beach refers to any beach open to the general public, regardless of whether an entry fee is charged, that provides access to bathing waters.
3. What qualifies as a semi-public beach?
   A semi-public beach refers to any bathing area with regular access by a specific group or organization, such as beaches associated with resorts, rental properties, community associations, summer camps, or beach clubs.
4. Who conducts water quality monitoring?
   Local health boards, the Barnstable County Department of Health and Environment, and the Massachusetts Department of Conservation and Recreation perform most beach water sampling statewide. The majority of marine beach samples from public beaches are analyzed by Massachusetts Department of Public Health (MDPH) contracted laboratories at no cost to municipalities.
5. How frequently is water tested?
   Testing frequency varies from daily to monthly depending on the beach's characteristics. Less frequently used beaches or those with historically few water quality issues undergo less frequent testing, while heavily used or problematic beaches receive more regular monitoring.
6. What bacteria are tested in beach water?
   Marine beaches are tested for Enterococci, a bacterial group in the Streptococcus genus. Some species (like Streptococcus faecalis) commonly occur in human and animal intestines and consequently in sewage. These serve as indicator organisms.
7. What are indicator organisms?
   These organisms help predict the presence of disease-causing pathogens associated with fecal contamination. While indicator organisms themselves are typically non-pathogenic, they share similar lifecycles and survival rates with pathogens and co-occur with them in human and animal waste.
8. What are the marine water quality standards?
   In marine environments, the acceptable Enterococci level for a single sample is 104 colony-forming units per 100 milliliters (cfu/100 ml) or below.
9. What happens when levels exceed standards?
   Any sample exceeding 104 cfu/100 ml is considered an exceedance. At most beaches statewide, if a sample exceeds standards but a follow-up sample taken the next day shows compliance, posting warnings becomes unnecessary. For beaches with a history of prolonged elevated bacteria levels (lasting over 24 hours), warnings remain required after each exceedance. A "history" means one or more consecutive exceedances in at least two of the previous four beach seasons.
10. What standards apply to freshwater beaches?
    Freshwater beaches must maintain Enterococci levels at or below 61 cfu/100 ml per single sample. This stricter standard reflects how higher bacterial concentrations in smaller water bodies (like lakes versus oceans) can pose greater infection risks. Freshwater beaches may alternatively be tested for E. coli, with an acceptable level of 235 CFU/100 ml or below.
11. Are beach warnings triggered by other methods?
    MDPH also employs a geometric mean standard based on the last five test results at a beach (excluding storm event samples). This geometric mean can indicate potential chronic water quality issues requiring attention.