Montgomery Lake
Sullivan County, New YorkView mapDirections
NY DEC publishes the water-quality measurements for Montgomery Lake. Here is what has been measured.
- Impaired · Nutrients (phosphorus, nitrogen)
- Limited data
Montgomery Lake in Sullivan County, New York has water-quality measurements published by NY DEC, shown here as reported. Water clarity: 13.9 ft visibility.
Montgomery Lake is a lake in Sullivan County, New York.
Source: EPA Water Quality Portal sampling records, NYSDEC, last sampled 2020-09-19. Methodology: how these readings are compared.
What Montgomery Lake is good for
From access and monitoring records, not editorial picks.
- Clear water13.9 ft of visibility
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. Montgomery Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Montgomery Lake is safe to swim in today is a call for the New York Department of Environmental Conservation and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Montgomery Lake
These are the measurements NY DEC publishes for Montgomery Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 13.9 ft. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 13.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Montgomery Lake
Answers come straight from the public measurements and survey records on this page.
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Stays near Montgomery Lake
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Fishing Montgomery Lake
EPA Impairment Status
Montgomery Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Recreation.
Source: EPA ATTAINS assessment unit NY1401-0091 · Official waterbody report
Regulated Pollution Sources Nearby
8 EPA-permitted facilities operate within about 5 miles of Montgomery Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Eldred PreserveEldred · 4 mi away · NPDES NY0281239Recent violation
- Aqua Pa Wastewater Inc Mast Hope WwtfLackawaxen · 4.7 mi away · NPDES PA0060496Recent violation
- 696 State Highway Route 580 Sftf (Fka David Holbert Sftf)Lackawaxen · 4.8 mi away · NPDES PA0065129Recent violation
- Barryville Shop - County DpwBarryville · 1.9 mi away · NPDES NY0264202
- Rudd HouseBarryville · 2.1 mi away · NPDES NY0219274
- New Hope Manor IncBarryville · 3.3 mi away · NPDES NY0207586
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 Sullivan County
Frequently asked questions about Montgomery Lake
Where is Montgomery Lake?
- Montgomery Lake is a lake in Sullivan County, New York. Its water-quality measurements are published by NY DEC and shown on this page as reported.
What is the water quality of Montgomery Lake?
- Montgomery Lake in Sullivan County, New York has water-quality measurements published by NY DEC, shown here as reported. Water clarity: 13.9 ft visibility.
Is Montgomery Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Montgomery Lake is listed impaired under Clean Water Act §303(d) (IR 5) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
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Where this data comes from
8 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- North American Lake Management Society
NALMS8 samples · 2020
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)