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LakeQuality

Hothole Pond-Deep Spot

C
Grade C — Fair
Fair · #31 of 41 lakes in the county · Mesotrophic
Mesotrophic

Hothole Pond-Deep Spot in Merrimack County, New Hampshire has a water quality grade of C (Fair). Phosphorus: 16.4 µg/L. Chlorophyll-a (algae): 5.9 µg/L.

Type
Mesotrophic
Public access
Yes

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Hothole Pond-Deep Spot is a mesotrophic lake in Merrimack County, New Hampshire. Water quality is graded C based on 2 sampling years through 2025. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 40 other monitored lakes in Merrimack County, Hothole Pond-Deep Spot ranks #31 for water quality.

Source: EPA Water Quality Portal sampling records, your state environmental agency, last sampled 2025-08-24. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Bacteria advisory

Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Generally safe for swimming, moderate water quality

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Water Quality Grade: C (Fair)

No clarity data. Phosphorus level: 16.4 µg/L. Chlorophyll-a: 5.9 µg/L. Trophic State Index: 46.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus16.4 µg/LFair
Chlorophyll-a (Algae)5.9 µg/LFair
Trophic State Index (TSI)46Mesotrophic

Moderate nutrients, good water quality

Where to stay near Hothole Pond-Deep Spot

Compare lakeside cabins, hotels, and vacation rentals near Hothole Pond-Deep Spot in Merrimack County, New Hampshire — 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.

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Recreation & Access

3
Boat Landings
Yes
Public Access
  • Hot Hole PondPublic
  • Merrimack RiverPublic
  • Turtletown PondPublic

Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps

Fishing Hothole Pond-Deep Spot

EPA Impairment Status

Hothole Pond-Deep Spot is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Algal growthBiotoxinsMercuryNutrients (phosphorus, nitrogen)pH / acidity

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit NHLAK700060302-05 · Official waterbody report · Matched by proximity (0.07 km)

County Ranking

Ranked #31 of 41 lakes in Merrimack County

Nearby Lakes in Merrimack County

Frequently asked questions about Hothole Pond-Deep Spot

Where is Hothole Pond-Deep Spot?

Hothole Pond-Deep Spot is a lake in Merrimack County, New Hampshire. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Hothole Pond-Deep Spot?

Hothole Pond-Deep Spot in Merrimack County, New Hampshire has a water quality grade of C (Fair). Phosphorus: 16.4 µg/L. Chlorophyll-a (algae): 5.9 µg/L.

Is Hothole Pond-Deep Spot safe to swim in?

Generally safe for swimming, moderate water quality. Hothole Pond-Deep Spot has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 5.9 µg/L. Always check local health department advisories before swimming.

Are there boat ramps on Hothole Pond-Deep Spot?

Hothole Pond-Deep Spot has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Hot Hole Pond, Merrimack River, Turtletown Pond. Public access is listed as yes.

Where this data comes from

60 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-21.

Collected and reported by

  • New Hampshire Department Of Environmental Services (BEACH)1111330060 samples · 2020–2025

Analytical methods

  • 10-115-01-1 F ~ LACHAT; Total Phosphorus- Manual persulfate digest
  • CHLOROPHYLL A-B-C DETERMINATION (MODIFIED)
Monitoring station identifiers (1)

Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.

Other records on this page

Impairment status from EPA ATTAINS 303(d) database

Named boat-access points from the USGS National Boat Ramps inventory