DNR Beach Policy
- The bacteria standard for Iowa’s recreational
waters consists of two components.
- A geometric mean standard based on 5 samples
in a 30-day period (126 colony forming units of E. coli
bacteria per 100 mL of water).
- A one-time maximum standard based on a single
sample (235 colony forming units of E. coli bacteria per 100
mL of water).
- Beaches are placed
on “vulnerable” list after two years of high geometric means in the most
recent 5 year period and removed from “vulnerable” list when this
condition no longer applies. One beach, Lake Darling, is being removed
from “vulnerable” list; while one new beach, Pine Lake, has been added
to the list.
- A new beach class
called “transitional” beaches is being added this year. This class
includes beaches where bacteria problems influencing the beaches have
been fixed or no longer pose a threat. Beaches on this list include
Lake Darling, Nine Eagles and Emerson Bay beaches. However, many more
beaches could be moved from the “vulnerable” list into this category
when problems are resolved. Furthermore, beaches in this transitional
class will be eligible to be removed from this list if they do not
exceed the geometric mean standard for one year.
beaches are all beaches that do not fall into the above categories.
Beaches that have had two or fewer one-time standard (samples
over 235 cfu/100 ml) exceedances of the state standard during a running five
years will be monitored less frequently. These beaches will be monitored on
a weekly basis from the week before Memorial Day through Labor Day. All
other state-owned beaches will be monitored from April 15th
through October 31st.
Posting of Signs/Advisories
- All beaches will be posted with signs that provide
general information regarding ways to reduce the health risk associated
with swimming at public beaches. These signs will also inform the
public of current monitoring efforts and ways to obtain the data.
- Beaches that exceed Iowa’s geometric mean water
quality standard for bacteria (the geometric mean of 5 samples in a
30-day period exceeds 126 colony forming units of E. coli
bacteria per 100 ml of water) will be posted with signs that state,
“Swimming is Not Recommended”. Posting will only occur between Memorial
Day and Labor Day.
- Beaches in the “vulnerable” and “transitional”
category (see list below) that exceed Iowa’s one-time maximum value (235
colony forming units of E. coli bacteria per 100 ml of water)
will immediately be posted with a “Swimming is Not Recommended” sign, if
high sample occurs between Memorial Day and Labor Day.
- DNR reserves the right to close a beach in the
event of a documented health risk including things such as (but not
limited to) wastewater by-pass, spills of hazardous chemicals, or
localized outbreaks of an infectious disease.
Beach Advisory Diagram
- Weekly DNR Press Releases regarding E. coli
numbers will not be issued. Results will continue to be posted on the
DNR website, along with the Water Monitoring website.
- County beaches that
express interest in bacteria monitoring will be provided with training
on monitoring techniques and funding to subsidize the cost of these
Beaches in the “vulnerable” category:
Beaches in the “transitional” category: