Blue Pit Lake
Cerro Gordo County, IowaView mapDirections
Iowa DNR publishes the water-quality measurements for Blue Pit Lake. Here is what has been measured.
- Mesotrophic
Blue Pit Lake in Cerro Gordo County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 17.1 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 2.4 µg/L.
Blue Pit Lake is a mesotrophic lake in Cerro Gordo County, Iowa. Overall water quality is improving over recent sampling years. Compared to the 3 other monitored lakes in Cerro Gordo County, Blue Pit Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2022-09-12. Methodology: how these readings are compared.
What Blue Pit Lake is good for
From access and monitoring records, not editorial picks.
- Clear water17.1 ft of visibility
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Blue Pit Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Blue Pit Lake
These are the measurements Iowa DNR publishes for Blue Pit Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 17.1 ft down. Phosphorus 20 µg/L. Chlorophyll-a 2.4 µg/L. TSI 41.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 17.1ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.4µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 41 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Blue Pit Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Blue Pit Lake typically sits around 68°F at the surface in September. Summer average is about 76°F. Usually warmest in Jul (about 80°F) and coldest in Sep (about 68°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (68°F) to its warmest (80°F).
Typical surface water temperature by month, from 9 field readings (2018–2022) via the EPA Water Quality Portal. See the full Blue Pit Lake water temperature breakdown →
Stays via Stay22
Stays near Blue Pit Lake
Compare lakeside cabins, hotels, and vacation rentals near Blue Pit Lake in Cerro Gordo County, Iowa — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Blue Pit Lake
Prices for Oct 23–25, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Iowa’s top lakes →
Follow Blue Pit Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fishing Blue Pit Lake
Water quality readings over time
3 seasons of samples on record (2020–2022). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Improving-20.1 µg/L/yr3 years
Chlorophyll-a
Improving-15.75 µg/L/yr3 years
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Blue Pit Lake under Clean Water Act (NPDES) discharge permits. 2 facilities have a reported Clean Water Act violation in the past three years.
- Heidelberg Materials Us Cement Llc (Remediation Site)Mason City · 2.5 mi away · NPDES IA0072907Recent violation
- Heidelberg Materials Us Cement LlcMason City · 2.5 mi away · NPDES IA0001945Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Cerro Gordo County
Frequently asked questions about Blue Pit Lake
Where is Blue Pit Lake?
- Blue Pit Lake is a lake in Cerro Gordo County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Blue Pit Lake?
- Blue Pit Lake in Cerro Gordo County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 17.1 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 2.4 µg/L.
Is Blue Pit Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Blue Pit Lake?
- Blue Pit Lake typically sits around 68°F at the surface in September, from 9 EPA Water Quality Portal field readings (2018–2022). That is a typical value for the month, not a live reading.
Explore Blue Pit Lake across LakeQuality
More lakes in Iowa
Other Lakes in Iowa
Mesotrophic Lakes in Iowa
Where this data comes from
36 measurements from 1 monitoring station, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX36 samples · 2020–2022
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- ISU modification of APHA 2130-B
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)