Sewer Project Reports and Conclusion








What are all the reports about?
You’ve probably heard people talking about a TMDL report and a Princeton Hydro report and you might be wondering what they’re all about. Well, you’re in luck. We’re going to summarize both reports for you here.

TMDL Report (Total Maximum Daily Load) for Phosphorus in Findley Lake
Prepared for US Environmental Protections Agency, Region 2 and New York State Department of Environmental Conservation. Prepared by: The CADMUS Group, Inc., July 2008.

The US EPA and NY State are required to develop Total Maximum Daily Loads (TMDLs) for all pollutants violating water quality standards in impaired water bodies like Findley Lake. Phosphorus (P) is the one pollutant requiring a TMDL and is primarily responsible for excessive weed growth and algae blooms that significantly impact recreational uses of the lake.

The TMDL for P is set at 242 pounds per year entering the lake from all external sources.

External sources of P are based on types of land use within the watershed and characterizations of septic systems based on distance from the lake combined with an estimate of seasonal homes. This information is then fed into a model that is adjusted for a best fit with actual P data obtained between 1990 and 2007.

External sources of Phosphorus, the current lbs./year of P entering the lake, the load allocations for each source and the reductions necessary to achieve the TMDL are shown in Table 6. With septic systems being 45% of the current total load (939 lbs./yr), there is no way to achieve the TMDL of 242 lbs./yr without eliminating septic systems.


  


Regarding Implementation, the report concludes: “This TMDL was written based upon the elimination of phosphorus loading from septic systems in conjunction with significant reductions from agricultural and developed lands. Meeting the necessary load reductions using this approach is the most technically achievable alternative. However, all of the reductions would be voluntary, so funding and public acceptance of this approach is essential to meeting the goals of the TMDL.”


Princeton Hydro Report
Findley Lake – Lake Evaluation and Recommendations

Town of Mina, Chautauqua County, NY, December 2021. Prepared for: Findley Lake Watershed Association. Prepared by: Princeton Hydro, LLC.

The Princeton Hydro report addresses the internal loading of Phosphorus (P) for Findley Lake. Internal Loading is when nutrients are introduced into the water – primarily from the lake sediment and decaying aquatic plants (weeds) and algae.

They designed a protocol to evaluate internal loading in the lake through sampling and modeling and to use this data to develop site specific recommendations for potential internal nutrient control. Such restoration techniques could therefore help reduce phosphorus loading and resulting harmful algal blooms. They conducted one water quality monitoring event on the lake at 3 locations in July 2021.

RESULTS

Results from one water quality monitoring event on the lake at 3 locations in July 2021 show the lake to be thermally stratified where the lake is separated into three distinct thermal layers. When this happens oxygen may become depleted in the deep/ cold waters and not able to be replenished from the atmosphere. And indeed, this is what was observed.

Surface waters were supersaturated with dissolved oxygen (DO), indicative of high rates of photosynthetic activity, and the deep water (below 15 feet) was depleted of oxygen (see red line in Figure 2.2). The low dissolved oxygen levels have important implications not only as unhabitable area for fish and other aquatic organisms but can also trigger the release of P fueling algal growth.




Elevated phosphorus in the deep waters may be indicative of internal sediment release of this nutrient under anoxic conditions. Princeton Hydro estimated that approximately 25% of the lake area (74 acres) go anoxic for a period of ninety (90) days. This correlates with an anoxic depth of approximately 15’ and greater.

INTERNAL LOADING ESTIMATE

The internal loading estimate for Findley Lake is 498 lbs./yr which is 35% of the total annual load (939 lbs./yr from external sources plus 498 lbs./yr internal sources = 1,437 lbs./yr P). Management of this load would likely produce tangible water quality benefits in a cost-effective manner for Findley Lake.

IN-LAKE MANAGEMENT OPTIONS

While in-lake management focuses on mitigating internal phosphorus release under anoxic conditions in-lake controls donot replace the need for ongoing watershed management including streambank stabilization, stormwater management, waterfowl management, and septic/sewer management.

Mitigating internal nutrient loading typically occurs in lake management via one of two means:

(1) Nutrient Inactivation by applying an aluminum compound (such as alum) to create a stronger bond with Phosphorus than Iron, thereby keeping the Phosphorus in the sediments under anoxia and now allowing it to be released into the water.

While alum has been used for over 40 years to control phosphorus, New York State is currently prohibiting the use of aluminum based nutrient inactivation projects. But they are evaluating this management technique and we’re hoping restrictions on the use of alum changes in the future.

If Alum were a permittable option, one application could prevent internal release over a period of 5-10 years. Princeton Hydro’s estimates the cost of Alum treatment to be in the $120,000 to $170,000 range if permissible by NYSDEC in the future.

(2) Destratification/ aeration the deep portions of the lake to maintain the iron-phosphorus bond during the summer months.

A destratification/ aeration system typically creates air bubbles that vertically circulate the entire water column thereby preventing both thermal stratification and anoxic zones that generate the release of Phosphorus into the lake. The system consists of air compressors and lines running to diffusers strategically located throughout the lake, especially within the lake’s deeper reaches. Destratification systems are operated continuously; typically starting in early- to late-spring (before thermal stratification occurs), throughout the entire summer until early fall (when stratification normally breaks down and the lake would naturally turn over).

Conclusion: Sewers are Crucial for Long-Term Water Quality of Findley Lake

We have significant and ongoing impairment of Findley Lake's water quality.

The TMDL and Princeton Hydro reports show that both internal loading and external loading are continually feeding the phosphorous problem in Findley Lake that is resulting in excessive weed growth and algal blooms. Our use of Findley Lake is already impaired and without significant changes, it will continue to get worse. Internal loading produces about 498 lbs./yr of P releasing from bottom sediments but we need to note that the P got into the sediment initially from an external source. External loading is the cause of 939 lbs./yr of P entering the lake with the septic systems being the largest chunk of that – currently at 425 lbs./yr.

For long-term improvement of the lake water quality, we need comprehensive solutions that address both internal loading and external loading.

Internal controls such as aeration, alum (if allowed by NY DEC), dredging, and continued use of weed harvesting to remove P within the biomass from the watershed can address a significant part of the problem. But, NY DEC grant funding for these options will only be considered after we address external sources (primarily septic systems). And if we only address the internal sources the lake will never get below the TMDL for P, which means we will forever have excessive weed growth and algae issues.

Examples of key external source controls include: erosion and sediment control using stormwater retention ponds, best management practices for agricultural runoff (note that the largest farm in our watershed already employs management practices that are monitored by the state – so not much more is likely to be gained here), and sewers.

So, what if we eliminated all internal sources and external sources except septic systems? We would still have 425 lbs./yr of P entering the lake from septic systems, which is 175% of the 242 lbs./yr limit to prevent ongoing degradation of the lake. The proposed sewer system is a required next step of a comprehensive solution if we hope to have significantly better water quality in Findley Lake for generations to come.

 





What are all the reports about?
You’ve probably heard people talking about a TMDL report and a Princeton Hydro report and you might be wondering what they’re all about. Well, you’re in luck. We’re going to summarize both reports for you here.

TMDL Report (Total Maximum Daily Load) for Phosphorus in Findley Lake
Prepared for US Environmental Protections Agency, Region 2 and New York State Department of Environmental Conservation. Prepared by: The CADMUS Group, Inc., July 2008.

The US EPA and NY State are required to develop Total Maximum Daily Loads (TMDLs) for all pollutants violating water quality standards in impaired water bodies like Findley Lake. Phosphorus (P) is the one pollutant requiring a TMDL and is primarily responsible for excessive weed growth and algae blooms that significantly impact recreational uses of the lake.

The TMDL for P is set at 242 pounds per year entering the lake from all external sources.

External sources of P are based on types of land use within the watershed and characterizations of septic systems based on distance from the lake combined with an estimate of seasonal homes. This information is then fed into a model that is adjusted for a best fit with actual P data obtained between 1990 and 2007.

External sources of Phosphorus, the current lbs./year of P entering the lake, the load allocations for each source and the reductions necessary to achieve the TMDL are shown in Table 6. With septic systems being 45% of the current total load (939 lbs./yr), there is no way to achieve the TMDL of 242 lbs./yr without eliminating septic systems.


  


Regarding Implementation, the report concludes: “This TMDL was written based upon the elimination of phosphorus loading from septic systems in conjunction with significant reductions from agricultural and developed lands. Meeting the necessary load reductions using this approach is the most technically achievable alternative. However, all of the reductions would be voluntary, so funding and public acceptance of this approach is essential to meeting the goals of the TMDL.”


Princeton Hydro Report
Findley Lake – Lake Evaluation and Recommendations

Town of Mina, Chautauqua County, NY, December 2021. Prepared for: Findley Lake Watershed Association. Prepared by: Princeton Hydro, LLC.

The Princeton Hydro report addresses the internal loading of Phosphorus (P) for Findley Lake. Internal Loading is when nutrients are introduced into the water – primarily from the lake sediment and decaying aquatic plants (weeds) and algae.

They designed a protocol to evaluate internal loading in the lake through sampling and modeling and to use this data to develop site specific recommendations for potential internal nutrient control. Such restoration techniques could therefore help reduce phosphorus loading and resulting harmful algal blooms. They conducted one water quality monitoring event on the lake at 3 locations in July 2021.

RESULTS

Results from one water quality monitoring event on the lake at 3 locations in July 2021 show the lake to be thermally stratified where the lake is separated into three distinct thermal layers. When this happens oxygen may become depleted in the deep/ cold waters and not able to be replenished from the atmosphere. And indeed, this is what was observed.

Surface waters were supersaturated with dissolved oxygen (DO), indicative of high rates of photosynthetic activity, and the deep water (below 15 feet) was depleted of oxygen (see red line in Figure 2.2). The low dissolved oxygen levels have important implications not only as unhabitable area for fish and other aquatic organisms but can also trigger the release of P fueling algal growth.




Elevated phosphorus in the deep waters may be indicative of internal sediment release of this nutrient under anoxic conditions. Princeton Hydro estimated that approximately 25% of the lake area (74 acres) go anoxic for a period of ninety (90) days. This correlates with an anoxic depth of approximately 15’ and greater.

INTERNAL LOADING ESTIMATE

The internal loading estimate for Findley Lake is 498 lbs./yr which is 35% of the total annual load (939 lbs./yr from external sources plus 498 lbs./yr internal sources = 1,437 lbs./yr P). Management of this load would likely produce tangible water quality benefits in a cost-effective manner for Findley Lake.

IN-LAKE MANAGEMENT OPTIONS

While in-lake management focuses on mitigating internal phosphorus release under anoxic conditions in-lake controls donot replace the need for ongoing watershed management including streambank stabilization, stormwater management, waterfowl management, and septic/sewer management.

Mitigating internal nutrient loading typically occurs in lake management via one of two means:

(1) Nutrient Inactivation by applying an aluminum compound (such as alum) to create a stronger bond with Phosphorus than Iron, thereby keeping the Phosphorus in the sediments under anoxia and now allowing it to be released into the water.

While alum has been used for over 40 years to control phosphorus, New York State is currently prohibiting the use of aluminum based nutrient inactivation projects. But they are evaluating this management technique and we’re hoping restrictions on the use of alum changes in the future.

If Alum were a permittable option, one application could prevent internal release over a period of 5-10 years. Princeton Hydro’s estimates the cost of Alum treatment to be in the $120,000 to $170,000 range if permissible by NYSDEC in the future.

(2) Destratification/ aeration the deep portions of the lake to maintain the iron-phosphorus bond during the summer months.

A destratification/ aeration system typically creates air bubbles that vertically circulate the entire water column thereby preventing both thermal stratification and anoxic zones that generate the release of Phosphorus into the lake. The system consists of air compressors and lines running to diffusers strategically located throughout the lake, especially within the lake’s deeper reaches. Destratification systems are operated continuously; typically starting in early- to late-spring (before thermal stratification occurs), throughout the entire summer until early fall (when stratification normally breaks down and the lake would naturally turn over).

Conclusion: Sewers are Crucial for Long-Term Water Quality of Findley Lake

We have significant and ongoing impairment of Findley Lake's water quality.

The TMDL and Princeton Hydro reports show that both internal loading and external loading are continually feeding the phosphorous problem in Findley Lake that is resulting in excessive weed growth and algal blooms. Our use of Findley Lake is already impaired and without significant changes, it will continue to get worse. Internal loading produces about 498 lbs./yr of P releasing from bottom sediments but we need to note that the P got into the sediment initially from an external source. External loading is the cause of 939 lbs./yr of P entering the lake with the septic systems being the largest chunk of that – currently at 425 lbs./yr.

For long-term improvement of the lake water quality, we need comprehensive solutions that address both internal loading and external loading.

Internal controls such as aeration, alum (if allowed by NY DEC), dredging, and continued use of weed harvesting to remove P within the biomass from the watershed can address a significant part of the problem. But, NY DEC grant funding for these options will only be considered after we address external sources (primarily septic systems). And if we only address the internal sources the lake will never get below the TMDL for P, which means we will forever have excessive weed growth and algae issues.

Examples of key external source controls include: erosion and sediment control using stormwater retention ponds, best management practices for agricultural runoff (note that the largest farm in our watershed already employs management practices that are monitored by the state – so not much more is likely to be gained here), and sewers.

So, what if we eliminated all internal sources and external sources except septic systems? We would still have 425 lbs./yr of P entering the lake from septic systems, which is 175% of the 242 lbs./yr limit to prevent ongoing degradation of the lake. The proposed sewer system is a required next step of a comprehensive solution if we hope to have significantly better water quality in Findley Lake for generations to come.